The 40 Most DANGEROUS Animals in the USA! (2023)

What are the most dangerous animals found in the United States?

It can be hard to decide what to consider dangerous. For example, maybe you consider any animal that bites or stings dangerous, but someone else is more worried about animals that cause car accidents! So with that in mind, I tried to include a mix of animals that are dangerous for different reasons. 

Remember that no matter what animal you encounter, it’s likely more scared than you are. Animals don’t want to mess with us, and it’s best to leave them alone and give them the space they deserve. That way, we can continue to co-exist with animals and observe them!

#1. Coyote

Identifying Characteristics:

• Adults range in length from 3 to 4.5 feet and weigh between 15 and 44 pounds.
• Their coloring is grayish to yellow-brown on top with white underparts.
• They have bushy tails, large, triangular ears, narrow muzzles, black noses, and yellow eyes.

Coyotes have a large range in North America and are found in various habitats, from the tropics to the tundra. Coyotes expanded their range after European settlers’ near extermination of wolves and cougars.

As with habitat, Coyotes are highly versatile in their food selection. Despite being primarily carnivorous, they consume various plants, including berries, grass, and food crops. They will eat almost anything, and this extensive menu allows them to thrive in nearly every environment in the United States!

Even if you haven’t seen one, you’ve probably heard a Coyote before! They’re extremely vocal and communicate through howls, yips, whines, and barks. These vocalizations are used to warn pack mates of danger, greet each other, and play.

Sadly, Coyotes are commonly hunted and trapped for fur and sport. Many people incorrectly assume these animals are dangerous to humans, but this isn’t the case. Sometimes, a Coyote will go after pets like small dogs or cats, but only if they’re left unattended. The best way to avoid Coyotes is to keep your pets on a leash outside and bring them in before dusk. 

#2. American Black Bear

Identifying Characteristics:

• Adults range from 5 to 6 feet tall and weigh 200 to 600 pounds.
• Coloration ranges from mostly black on the east coast to brown, cinnamon, or blonde in the West, and blue-gray or creamy white in some populations.
• They have flat backs, small heads, rounded ears, and non-retractable claws.

American Black Bears occupy various habitats in the United States but generally prefer inaccessible terrain.

Black bears are sometimes considered a nuisance because they can damage cornfields, honeybee hives, and berry farms. In addition, they‘re easily attracted to garbage, bird feeders, and coolers. Make sure NEVER to feed them, as this can make the bear not afraid of humans, which is dangerous for both you AND the bear. 

Generally, Black Bears are timid around people. Unlike grizzly bears, females with cubs rarely attack people, often just sending their cubs up a tree so that they can retreat safely.

Black Bears are naturally active in the evening and early morning but sometimes alter their activity patterns for food availability. Bears may become active during the day when garbage and other human food sources are available. Black Bears in campgrounds often develop nocturnal activity patterns.

Contrary to popular belief, Black Bears don’t truly hibernate.

Instead, they enter a state of shallow torpor. In this state, their body temperature decreases, their metabolism slows, and they don’t need to wake to eat, drink, urinate, or defecate. Consequently, Black Bears must put on a heavy layer of fat in the fall to survive through winter and spring.

#3. Brown Bear (Kodiak/Grizzly)

Identifying Characteristics:

• Adults are between 3 to 5 feet tall on all fours or up to 9 feet standing on hind legs and weigh 200 to 1,000 pounds.
• Coloration can range from black to blonde.
• They have a distinct shoulder hump, disc-shaped face, and long claws.

Brown Bears, Grizzly Bears, and Kodiak Bears are a single species, Ursus arctos.

The term Brown Bear often refers to those that live on the coast. Bears that live inland are often smaller and generally referred to as Grizzlies. Kodiak Bears (Ursus arctos middendorffi) live on the Kodiak Archipelago and have been isolated from mainland populations since the last ice age, about 12,000 years ago.

All three share the same basic physical characteristics; for this guide, we will call them Brown Bears. They occupy various habitats, including desert edges, high mountain forests, ice fields, tundra, alpine meadows, and coastlines. They prefer areas with dense cover in which they can shelter. Before the arrival of European settlers, Brown Bears were also found in the Great Plains.

Brown Bears are normally slow, but if needed, they can run up to 35 miles per hour! They also swim as they prey upon fish or cross rivers. Unlike the black bear, adult Brown Bears generally aren’t adept at climbing trees due to their size and weight. However, they have an excellent sense of smell, which they use to locate food.

Brown Bear populations are drastically reduced from their number before the westward movement of European settlers. Some estimates indicate that Brown Bears occupy just 2% of their former range. Today, they face threats from habitat destruction due to logging and mining and the development of roads, subdivisions, golf courses, and resorts.

Unfortunately, Brown Bears also have a reputation for being aggressive and dangerous to humans. In reality, they’re attracted to improperly stored food, but they prefer not to encounter people. When camping or hiking, keep your food items in bear-safe containers. If you see a Brown Bear, leave it alone and give it plenty of space. 

#4. White-Tailed Deer

Identifying Characteristics:

• Adults range from 63 to 87 inches long and stand between 31 and 39 inches tall at the shoulder.
• Their coloring is tan or brown during the summer and grayish in winter, with white on the throat, chest, and underside of the tail.
• The males have antlers which they shed in the winter.

White-tailed Deer are found in various habitats in the United States.

These large animals are common to see living near people as they are completely comfortable in suburban environments. The herd in my neighborhood is particularly fond of our bird feeders. They stop by for a snack almost every evening!

There aren’t many things cuter than a baby deer! The fawns are born with white spots and can walk almost right away. The mother may leave the fawns to forage for hours at a time, which can be disconcerting to see.

While their mother is away, the scentless fawns lay flat on the ground, their necks outstretched, and they’re well camouflaged. The female deer always come back to the baby, so don’t disturb the fawn if you find one!

The reason we consider White-tailed Deer to be dangerous is because they’re so prevalent near roads and highways. They frequently cause car accidents because they often run across roads at night or dusk. So keep alert if you live in an area with a deer population, especially during spring and fall!

#5. Wild Boar

Identifying Characteristics:

• Adults range from 5 to 8 feet in length and weigh between 145 and 600 pounds.
• Their thick, coarse hair ranges in color from black to reddish-brown.
• They have large heads and necks and relatively short legs. Males have long bristly hairs down the middle of their backs and large canines that protrude from the mouths of adult males.

Wild Boars occupy various habitats but prefer areas with water sources and some dense vegetation for shelter. They generally don’t thrive in habitats with extreme heat or cold.

These mammals are omnivores, and what they eat varies with season and location. They consume large amounts of plant matter, including fruits, nuts, roots, herbaceous plants, and crops. They also eat bird eggs, carrion, small rodents, insects, and worms. Their voracious appetite can be very detrimental to an ecosystem, causing a loss of plant diversity and extensive soil erosion.

Wild Boars are invasive mammals in the United States, as they were introduced from overseas. Their population has exploded in the last 50-100 years, leading wildlife departments to implement population control programs.

Because of their aggressive nature and lack of fear, Wild Boars can be dangerous to livestock, humans, and pets. Hunting this species in most places is illegal because controlled hunts and cullings are organized to deal with invasive populations. If you have a Wild Boar on your property or see one while you’re out and about, call your local animal control office for advice. DON’T try to approach this unpredictable animal!

#6. Rats

Interestingly, brown and black rats (the most common types that cause disease) are not native to the United States. They’re thought to have originated in the eastern hemisphere and were brought here through trade routes. Living in a highly populated city makes you more likely to see a Brown Rat. Black Rats, on the other hand, usually live in agricultural and farming communities.

Even though both species are still common, in many areas where the Black Rat was once the dominant species, the Brown Rat has taken over. Black Rats are slightly smaller and reproduce less often, two reasons this species isn’t as widespread as Brown Rats.

Most people consider rats of any species to be pests, both in the agricultural market and in homes and cities. Like other rodents, Black and Brown Rats can carry pathogens in their bodies. While they may not appear sick, they can spread infections like toxoplasmosis, typhus, and bubonic plague. Avoid handling wild rats, and be especially careful of their bite!

#7. White-footed Deer Mouse

Like most other mice, this species is a vector, which carries and spreads disease.

Many rodents can carry disease-causing pathogens without getting sick, making them ideal carriers for these germs. For example, White-footed Mice transmit Hantavirus and the bacteria that cause Lyme disease.

White-footed Deer Mice are one of the most likely species you will find in your attic, garage, or basement. Even though they can spread disease, contamination isn’t very common in homes.

This is the species I’ve found in my house, and I use a live trap and release them in a field a few miles away. Here’s the trap that I use!

View on Amazon

#8. Moose

Identifying Characteristics:

• Adults stand about six feet at the shoulder and weigh over 1,000 pounds.
• Their coloring is generally dark brown. Cows (females) have light brown face and a white patch of fur beneath the tail.
• Moose have flaps of skin called dewlaps hanging from their throats, and bulls (males) grow massive antlers up to six feet across in the spring and summer.

Moose, the largest member of the deer family, only thrive in colder climates due to their massive size and insulated fur. In addition, their hair is hollow, helping to trap air and provide maximum insulation. Their ideal habitat includes a mix of mature and young trees, which provides abundant forage.

I was surprised to learn that Moose are named for their diet! The word “moose” is an Algonquin term that means “eater of twigs.” They feed on woody material from trees. During the summer, they also eat large quantities of aquatic plants. A single moose consumes 25 to 45 pounds of vegetation per day.

Female Moose, called cows, are known to aggressively defend their young, which often have a high mortality rate until they turn one. Mothers have been known to injure or kill grizzly bears, wolves, black bears, and even people in defense of their babies. If you encounter a Moose with babies, stay as far away as possible to avoid injury.

Moose are highly susceptible to the effects of climate change. Warmer winters have resulted in higher tick infestations, causing Moose to die of blood loss and anemia. Tick infestations are believed to be the main cause of Moose populations dropping 40% in the last decade.

#9. North American Porcupine

Identifying Characteristics:

• Adults range from 2 to 3 feet long and weigh about 20 pounds.
• Their fur ranges from brownish-yellow to black, with white highlights on their quills.
• Porcupines are covered in approximately 30,000 hollow quills.

While North American Porcupines generally spend much of their time on the ground, they can also climb trees, using their tail for support. But they aren’t the best climbers; researchers examined wild porcupines and found that 30% had healed fractures from falling out of trees! They‘re well known for their sharp quills used for defense. When threatened, porcupines draw up the skin of their back, bristling so that the quills face all directions. The porcupine keeps its back to the predator and moves its tail back and forth. But, despite their effective defense, porcupines are still preyed on by fisher cats, coyotes, wolverines, and other predators that have adapted to hunting them.

Contrary to popular belief, porcupines can’t throw quills at their attacker! 🙂 However, you should keep your eyes open for these animals while hiking. After all, their quills will do serious damage if a clumsy Porcupine happens to fall on you!

#10. Striped Skunk

Identifying Characteristics:

• Adults range from 18 to 32 inches long.
• Their coloring is black with two thick white stripes running down the back and tail and a thin white stripe from the snout to the forehead.
• They have a bushy black tail, small triangular heads, short ears, and black eyes.

Striped Skunks have the worst reputation of any animal in the United States.

They’re best known for their unique defense system. A Striped Skunk will first stomp its feet or handstand as a warning when threatened. Then, if they aren’t heeded, the skunk bends its hindquarters to face the animal and releases its smelly defensive spray. While it may not be technically dangerous, the unpleasant, oily liquid can reach up to 20 feet and may cause nausea, intense pain, and temporary blindness.

Despite their foul odor, Striped Skunks provide benefits to humans in the form of pest control. In the summer, they’re largely insectivorous and feed heavily on grasshoppers, crickets, beetles, and bees. The best thing to do if you see a skunk is to give it space. They usually move on quickly when they notice humans!

Striped Skunks have stable and abundant populations. However, some local populations have been affected by rabies outbreaks. In addition, Striped Skunks face threats from severe weather, chemical exposure, and vehicle collisions.

These small mammals are typically very common in suburban areas but are rarely seen because they are nocturnal. As seen below, they often visit bird feeders to eat leftover seeds on the ground!

#11. Cougar

Identifying Characteristics:

• Adults stand 24 to 35 inches tall at the shoulder and weigh between 64 and 220 pounds.
• Coloration ranges from reddish-brown to tawny or gray, with a black tip on their tail.
• They have round heads, pointed ears, and powerful forequarters.

Their large hind legs and massive paws help give Cougars incredible athletic ability. They can jump 15 feet high and 40 feet in distance and sprint 50 miles per hour. Yet, despite their impressive speed, they generally wait and ambush prey.

Except for females raising young, adult Cougars generally only kill one large animal every couple of weeks. Then, they drag the kill to a preferred area and cover it with brush, returning to feed off it over a few days.

While cougars don’t have any predators besides humans, they may get into territory conflicts with other large predators. Cougars dominate one-on-one confrontations with wolves but are weaker when confronting packs. Generally, brown and black bears can drive off cougars with little effort.

Unfortunately, their territorial nature can sometimes spill over into conflicts with humans. In particular, mothers with young cubs are known to stalk and lunge at hikers. 

You may know this dangerous animal by a different name depending on where you live.

While Cougar seems to be the most common, these large cats are also known as catamount, mountain lion, puma, ghost cat, and panther.

#12. 9-Banded Armadillo

Identifying Characteristics:

• Adults are about 2.5 feet long from nose to tail and weigh approximately 12 pounds.
• Their back, sides, head, tail, and outer legs are covered in bony, armor-like plates connected by flexible bands of skin.
• Tough skin and coarse hair cover the underside.

This species is one of the most unique-looking mammals in the United States!

A common misconception is that 9-Banded Armadillos roll up into a ball when threatened. In reality, this species is much more likely to burrow for protection.

9-Banded Armadillos have an incredible system of reproduction. Every time this species gets pregnant, the zygote splits into four identical quadruplets. They’re the only animal that produces offspring this way, and scientists aren’t sure why it happens.

Two reasons 9-Banded Armadillos are considered dangerous animals are car accidents and disease. These slow mammals often cross busy roads and highways, stopping traffic or causing accidents that can injure humans. Additionally, they are a carrier of the bacteria that causes Leprosy, an infection that can cause joint pain, skin ulcers, and permanent disfigurement if left untreated.

If you see an Armadillo, it’s best to keep your distance and admire this interesting but strange mammal from afar. 

#13. American Bison

Identifying Characteristics:

• Adults stand up to 6 feet tall, and males can weigh more than one ton while females reach 900 pounds.
• They have long, deep brown fur, cloven hooves, and a noticeable hump over their shoulders.
• Both males and females have short, curved, hollow horns that can grow up to 2 feet.

While you may have heard them called buffalo, the correct name for this species is American Bison. Buffalo are native to Africa and Asia, while Bison, a distantly related animal, is native to North America.

Bison are well adapted to the changing seasons across their range. They’re constantly on the move, walking even while eating. To forage during the winter, they use their large heads to sweep aside the snow. During summer, Bison often wallow, rolling on the ground and creating shallow depressions in the soil. Wallowing helps them to cool off and soothe insect bites.

American Bison were once widespread, but by 1900, as few as 1,000 bison remained. While some Bison were hunted for food, most were killed for sport and to drive out Native American groups that relied on Bison as settlers expanded westward. Finally, in the 1900s, they received federal wildlife protection and were brought back from the brink of extinction. Today, approximately 31,000 wild bison are found on federally protected lands and reserves.

Bison can be dangerous animals if they are approached.

These animals are impossibly large and agile. If you don’t respect their space, they won’t hesitate to charge. They can easily break bones and trample humans. So, always remember to keep a safe distance and remain respectful of these animals. 

#14. Elk

Identifying Characteristics:

• Adults stand 4.5 to 5 feet tall at the shoulder and weigh between 400 and 800 pounds.
• Their coloring is light brown with a dark brown shaggy mane from neck to chest in winter and reddish-brown in summer.
• They have thick bodies, short tails, and long legs, and bull (male) Elk grow massive antlers yearly.

The Elk is one of the largest mammals in the United States.

They can be found in deciduous woodlands, boreal forests, mountainous areas, and grasslands. Most populations migrate seasonally. During the spring, they follow the retreating snow, traveling to higher elevations to graze. In the fall, they return to lower elevations and wooded areas that afford greater food availability.

Elk are herbivores that consume an average of 20 pounds of plant material daily! Elk are ruminants, meaning they have four-chambered stomachs. This trait allows them to eat quickly and then move to more sheltered areas to digest their food.

You should never approach Elk because they are dangerously unpredictable.

In fall and winter, males are belligerent and territorial while they search for mates. Then, in the spring, females become the aggressors as they look after their young. No matter the season, you should keep your distance and observe these dangerous animals from afar.

#15. Domestic Dogs

There’s a good reason why dogs are considered “man’s best friend.”

They’re one of the most popular pets in the United States! However, usually due to poor training or mistreatment, dogs can easily become dangerous animals. 

No matter what breed, size, or disposition, any domesticated dog has the potential to hurt a human. For example, if you don’t pay attention to a dog’s warning cues, it may become defensive and bite or jump to get you to back off. 

To ensure you stay safe, never approach a dog you don’t know, and always ask its owner before you greet it. If you have a dog yourself, don’t leave it unsupervised with children or strangers to decrease the risk of accidental conflict. Finally, and most importantly, learn to follow your dog’s lead regarding their social cues. A dog that feels threatened is always dangerous, no matter how loyal they are!

#16. Copperhead Snakes

Identifying Characteristics:

• Adults reach lengths between 20 and 37 inches.
• Stout bodies, broad heads, and elliptical pupils.
• Coloration varies from pale tan to pinkish-tan with darker, splotchy, hourglass-shaped bands, which are darker at the edges and thinner towards the center of the back.

Look for these venomous snakes in the United States in deciduous forests and mixed woodlands, often near rocky outcroppings. However, they may also be seen in swampy areas, coniferous forests, and near river habitats. They’re active during the day in the spring and fall when the weather is cooler. During the middle of summer, Copperheads are often nocturnal.

Copperhead Snake Range Map

Credit: Virginia Herpetological Society

These snakes are ambush hunters, meaning that they select a suitable site and wait to surprise their prey. In addition, copperheads are considered “pit vipers,” meaning they have a heat-sensing organ between their eyes. This adaptation helps these venomous snakes locate and judge the size of their prey by sensing infrared heat!

Bites from these venomous snakes are rarely fatal in the United States.

The venom they produce has relatively low potency. In addition, copperheads also frequently employ false strikes, dry bites, and warning bites. Dry bites contain no venom, and warning bites have a relatively small amount of venom.

Despite their low fatality, Copperhead venom is hemotoxic, destroying blood cells and tissue. It can cause localized swelling, necrosis, and severe pain. If bitten, medical attention should be sought.

When threatened, Copperheads use a freeze defense. Their excellent camouflage coloration allows them to blend into the leaf litter and soil. However, they may also vibrate their tails in the leaves when approached to produce a buzzing sound. This noise may serve to warn predators, similar to a rattlesnake, or divert a predator’s attack to their tail. If they continue to be disturbed, they may deliver false strikes or bite.

#17. Timber Rattlesnake

Identifying Characteristics:

• Adults typically range from 30 to 60 inches in length.
• Coloration is variable and generally ranges from yellowish brown to gray to almost black. Look for dark brown or black crossbands on their back.
• Heavy-bodied with a characteristic rattle on the tail.

The Timber Rattlesnake, also known as the Canebrake Rattlesnake, can be found in various habitats in the United States. Look for these venomous snakes in lowland thickets, high areas around rivers and flood plains, agricultural areas, deciduous forests, and coniferous forests.

Timber Rattlesnake Range Map

Credit: Virginia Herpetological Society

These venomous snakes are ambush predators, waiting for unsuspecting prey to come within range of their strike. They feed primarily on small mammals but may also consume frogs, birds, and other smaller snakes. Timber Rattlesnakes strike their prey and release them, waiting until the venom has taken effect before eating them.

These venomous snakes are potentially the most dangerous species in the United States due to their large size, long fangs, and high venom yield. Luckily, Timber Rattlenskaes have a mild disposition and don’t often bite. They typically give plenty of warning by rattling and posturing.

The Timber Rattlesnake has played an interesting role in US history. As it can be found in the area of the original 13 Colonies, it was used as a symbol during the American Revolution. In 1775 it was featured at the center of the “Gadsden Flag.” This yellow flag depicts a coiled and ready-to-strike Timber Rattlesnake and the words “Don’t Tread on Me.”

#18. Eastern Massasauga

Identifying Characteristics:

• Adults are typically around 2 feet in length.
• Coloration is gray or light brown with darker chocolate-brown blotches on the back and smaller ones on the sides, which feature light edges.
• Thick body, vertical pupils, heat-sensing pits between the eyes and nostrils, and a heart-shaped head.

These small venomous snakes live primarily in wet habitats in the United States.

The name “Massasauga” actually comes from the Chippewa language and means “great river mouth” and describes their habitat. Look for them in floodplain forests, shrub swamps, low areas along rivers and lakes, wet prairies, moist grasslands, bogs, and marshes. During the summer, they often migrate to drier regions adjacent to these habitats.

Eastern Massasauga Range Map

Unlike other rattlesnakes, the Eastern Massasauga hibernates alone. They frequently hibernate in crayfish burrows but may also use small mammal burrows or spaces under rotting logs or tree roots. Dens must be below the frost line, or they risk freezing to death!

These snakes have cytotoxic venom that destroys tissue, which also has the dangerous quality of disrupting blood flow and preventing clotting. But these snakes are secretive, shy, and avoid humans when possible. The only times they bite seem to be when handled or accidentally stepped on!

This venomous snake is listed as threatened, endangered, or a species of concern in all parts of its range. Historically, these snakes have faced pressure from hunting, and many states had bounties and roundups for them. Today they are still often killed out of fear AND face diminishing wetland habitats.

#19. Cottonmouth Snakes

Identifying Characteristics:

• Adults range from 26-48 inches long.
• Most individuals are dark gray to black with a broad head, heat-sensing pits between the eyes and nostrils, elliptical pupils, and a blunt snout.
• Some individuals have a brown, gray, tan, or blackish coloration.

Cottonmouths are the ONLY aquatic venomous snakes in the United States.

Be on the lookout for them near bodies of water, including swamps, marshes, ponds, and slow-moving streams and rivers, as well as semi-permanent water sources like flooded fields and drainage ditches. But they aren’t limited to just aquatic habitats and can also be found in palmetto thickets, pine forests, dune areas, and prairies.

Cottonmouth Snake Range Map

Credit: Virginia Herpetological Society

Since they are typically near water, the bulk of their diet is made up of fish and frogs. But they are opportunistic and will also eat small mammals, birds, turtles, small alligators, and other snakes.

Interestingly, when hunting in the water, they typically hold their kill in their mouth while the venom takes effect. But when hunting on land, they release their prey, such as rodents, and track it to consume once it dies. The thought is that land animals, like rodents, are more likely to bite back, so it makes sense to make sure they are dead.

These venomous snakes, also called Water Moccasins, Black Moccasins, or Gapers, have several defensive tactics. For example, they often vibrate their tail in the leaf litter, pull their heads up and back, and then open their mouth to hiss and expose a white interior. This particular display is what earned them the name “cottonmouth.”

Luckily, receiving a bite from a Northern Cottonmouth is rare. But when it does happen, it is very serious. Their venom destroys the tissue and is more toxic than a copperhead but not as severe as a rattlesnake. It is rare to die from their bite, but it does cause swelling and bruising and can leave scars.

#20. Eastern Diamond-backed Rattlesnake

Identifying Characteristics:

• Adults typically range from 3 to 6 feet long!
• Coloration is a mixture of browns, yellows, grays, or olive. Look for the distinctive diamonds that run down their back.
• A black band covers the eyes, which have vertical, cat-like pupils. A pit between the eye and nostril is present on each side, and adults have their distinctive rattle.

This species is the longest, heaviest venomous snake in the United States!

Some impressive individuals have even grown up to 8 feet long. They prefer relatively dry habitats, including pine forests, palmetto flatwoods, mixed woodlands, and scrublands. However, they can also be spotted around the borders of wetlands and in wet prairies and savannas. The best time to look for these rattlesnakes is during the morning and evening, as this is when they are most active.

Eastern Diamond-backed Rattlesnake Range Map

These impressive venomous snakes can strike as far as two-thirds of their body length, meaning a six-foot individual can reach prey four feet away! When attacking, they inject their prey, which includes mice, rabbits, and squirrels, with venom. Once their victim is bitten, they release it, and they track it to the place it has died to consume.

As you may have guessed, Eastern Diamond-backed Rattlesnakes typically issue a warning with their rattle when threatened. If you hear this sound, back away and move along, or you risk being bitten. Interestingly, young snakes don’t have a rattle, as it grows as they get older. Each time an individual sheds their skin, a new section is added (though sections commonly break off).

During the breeding season, males will fight for dominance. They lift their bodies and try to throw the other on the ground. And once born, these venomous snakes can live for 20 years or more!

#21. Western Diamond-backed Rattlesnake

Identifying Characteristics:

• Adults typically grow to about 4 feet in length.
• Coloration ranges from brown, gray, brick red, pinkish, and chalky white. Look for the darker diamond-shaped blotches down its back, outlined by white scales.
• Broad, spade-shaped head with a black mask over the eyes. Elliptical pupils and pits between eyes and nostrils.
• A rattle on the tail alternates between black and white-colored bands.

This famous venomous snake has a wide range of habitats in the United States!

You might spot them in deserts, grassy plains, forested areas, coastal prairies, rocky hillsides, and river bottoms. But your best chance to see one might be on a rural road in the evening because of the heat the pavement retains.

Western Diamond-backed Rattlesnake Range Map

Western Diamond-backed Rattlesnakes hibernate in communal caves, dens, or rock ledges called hibernacula during the winter. They sometimes share these spaces with snakes of other species and can survive in hibernation for several months without eating.

The Western Diamond-backed feeds on small mammals such as squirrels, chipmunks, gophers, prairie dogs, rabbits, mice, and rats. They will also consume birds that fly within reach. Like other pit vipers, they ambush their prey and track them while the venom takes effect.

When threatened, the Western Diamond-backed will typically stand its ground. They rattle and coil, lifting themselves off the ground to prepare to strike.

If you hear their characteristic rattle, leave the area slowly! Due to their specialized fang and large venom glands, these snakes can deliver a lot of venom in a single bite! Untreated bites have a mortality rate of 10 – 20%, so make sure to get to the hospital quickly if struck!

#22. Prairie Rattlesnake

Identifying Characteristics:

• Adults typically range between 3.3 and 5 feet in length.
• Coloration is highly variable and can be greenish-gray, olive green, greenish-brown, light brown, or yellow. All variations have dark blotches on the body that turn into rings near the tail.
• Broad triangular head, elliptical pupils, heat-sensing pits between the eyes and nostrils, and a tail rattle.

These venomous snakes can be found in the United States in open prairies, grasslands, semi-desert shrublands, and forested environments. They can even be found at elevations up to 9500 feet!

Prairie Rattlesnake Range Map

When they feel threatened, these snakes will freeze, trying to use their camouflage to avoid detection. They may also quietly crawl away to cover. If approached, they coil and rattle their tail as a warning before striking. Their potent venom has both hemotoxic and neurotoxic properties, and although bites are rare, they can be fatal to an adult human.

#23. Pygmy Rattlesnake

Identifying Characteristics:

• Adults are small and range from 1 to 1.5 feet in length.
• Coloration varies, as there are three subspecies of Pygmy Rattlesnake.
• Thick body, dark bands that run from the corners of the eyes to the jaw, a small rattle prone to breaking, and elliptical pupils.

This species is the smallest venomous snake found in the United States!

Pygmy Rattlesnakes occupy a wide variety of habitats. Naturally, they can be found in pine forests, dry upland forests, floodplains, sandhills, and near lakes, rivers, and marshes. In addition, they are often encountered in urban areas and may be seen in gardens and brush piles.

Pygmy Rattlesnake Range Map

These venomous snakes are rarely seen because they are so small and well-camouflaged. When found, they typically remain silent and motionless and rely on blending into their environment. It’s rare to hear them rattle. When they do, it sounds more like a faint insect and can be hard to hear unless you’re within a few feet of one.

Due to the Pygmy Rattlesnake’s small size, a bite typically isn’t fatal to healthy adults and is considered less severe than the bite of most other venomous snakes. But make no mistake, these snakes’ cytotoxic venom can cause pain and necrosis. You should see a doctor if you’re bitten.

#24. Western Rattlesnake

Identifying Characteristics:

• Adult size varies widely over their range, with the largest individuals being 6 feet long.
• Coloration varies greatly and can be dark brown, yellowish, dark gray, or olive brown.
• Triangular head, heat-sensing pits between the eyes and nostrils, dark stripe with white borders that runs from the eye towards the jaw.

Also known as the Northern Pacific Rattle Snake, this venomous species occupies many habitats. They can be found in mountainous areas, woodlands, and grasslands. They also often occur close to humans. It’s this proximity that makes them dangerous animals. Because they live so close to people, we come in contact with them much more often than other species. However, bites are still rare. Keep your eyes peeled for this snake and give them room if you encounter one.

Western Rattlesnake Range Map

Western Rattlesnakes have excellent camouflage and unique coloring, as these snakes show considerable variation. When they’re young, they have a distinct color pattern, but it fades over time as the snakes mature.

These snakes may be active during the day or night and often curl up, waiting to ambush various prey. They’ll feed on small mammals, birds, reptiles, and amphibians. They may also eat bird eggs, and young snakes often feed on insects.

Like other rattlesnakes, this species gives birth to live young. Healthy, sexually mature females can give birth to litters of up to 25 babies!

#25. Coral Snakes

• Genus: Micrurus/Micruroides

Identifying Characteristics:

• The different species vary in length, usually from 11-30 inches.
• They’re a mix of yellow, red, and black coloring, sometimes with white or yellow bands.
• Their body shape is usually slender, with a slightly pointed head.

Coral snakes are some of the most dangerous animals in the United States. They primarily feed on frogs, lizards, and other smaller snakes. Their venom is a potent neurotoxin that causes rapid paralysis and respiratory failure for their prey.

Rarely seen by humans, these nocturnal venomous snakes spend most of their time underground. Because of this fact, and because they’re not very aggressive, Coral Snakes rarely bite humans. When they do bite, the venom is seldom deadly when medical treatment is immediately sought. However, they should still be treated with care if found!

Interestingly, when threatened, these snakes often pass gas. Listen for a popping sound made by expelling air from their cloaca. Scientists believe this may be a mechanism to ward off predators.

#26. Common Snapping Turtle

Identifying Characteristics:

• They weigh 10 to 35 lbs. and grow 8 to 18 1/2 inches long.
• The snapping turtle has a long tail, chunky head, and large webbed feet.
• The carapace (upper shell) coloring is black, brown, or olive with no distinct pattern.

These prehistoric-looking reptiles are widespread throughout the United States.

Look for them living in marshes, lakes, ponds, rivers, and slow streams. They prefer areas with plenty of aquatic vegetation to hide in and insects, fish, frogs, and birds to eat.

Snapping Turtle Range Map

Credit: Virginia Herpetological Society

Snapping Turtles are best known for their powerful jaws. While there aren’t any recorded incidents of one of their bites causing amputation to a person, it can cause infections serious enough to require an amputation. In fact, their jaws are so strong that snapping turtles commonly eat other turtles!

These reptiles are usually docile but will become very aggressive if removed from the water. One of the best ways to calm an aggressive individual is to place it back into the water, where it can feel safe. I know I have personally picked them up with a large snow shovel to get them off the road and back to safety!

#27. American Alligator

• Alligator mississippiensis

Identifying Characteristics:

• 6 to 16.5 feet long. A record individual was found to be 19 ft. 2 in.!
• The broad, rounded snout sets it apart from other crocodilian species.
• Coloring is dark gray to olive, sometimes nearly black.

The American Alligator is the largest reptile in the United States!

They live in tropical and subtropical regions with access to freshwater rivers, lakes, and swamps. Although they sometimes venture into brackish water, they can’t stay in the salty water very long.

American Alligators are widely studied and one of the most interesting reptiles in the United States. They can reach enormous lengths and weigh well over 500 pounds. Seeing them basking on a shoreline or swimming through the water is a remarkable experience. They‘re unique among reptiles because of one incredible skill: These amazing animals have been observed using lures to attract prey, especially birds.

Many people consider American Alligators the most dangerous animal in the United States.

However, incidents involving alligator attacks are statistically few and far between. They’re often content to stay away from people unless they’re baited into attacking or directly confronted. Occasionally, they can cause car accidents if they happen to cross a busy highway. The best way to avoid danger is to avoid alligators themselves by paying attention to signage and keeping alert for these animals. 

#28. Gila Monster

Identifying Characteristics:

• 9 to 14 inches long.
• This species is large and heavy, with a short, thick tail.
• The coloring is black, mottled with pink, orange, and yellow. The pattern of mottling often looks like beadwork.
• The scales on the back of the Gila Monster are rounded and beadlike. Scales on the belly are flat and square.

The Gila Monster is the ONLY venomous lizard in the United States.

It’s recognizable by its thick body and tail and rounded nose. Gila Monsters prefer rocky desert habitats with sparse brush or succulent plant life. Look for them near intermittent streams and farm irrigation systems, which they use as a water source.

Gila Monsters are venomous, but they rely more on their powerful crushing jaws to subdue their prey. They eat small mammals, birds and their eggs, lizards, insects, and carrion. While they primarily stay on the ground, Gila Monsters climb rocks or trees searching for food like small birds in nests. 

If you find a Gila Monster, observe this dangerous animal from a safe distance!

Though it isn’t fatal, the Gila Monster’s Bite is excruciating. They have small, razor-sharp teeth that dig into the skin and inject their venom. Unfortunately, there’s no anti-venom or treatment for the effects of the bite. People who’ve been bitten by a Gila Monster describe the pain as hot lava coursing through their veins!

The effects can last for hours or days, depending on how much venom someone is exposed to. It’s definitely not something you want to experience firsthand!

#29. Colorado River Toad

Identifying Characteristics:

• Adult length is 4-7 ½ inches; the Colorado River Toad is the largest toad native to North America.
• Very large glands on either side of the head produce its powerful venom.
• Their coloring is dark brown or olive to gray, with smooth skin and a few warts located on the hind legs.

The Colorado River Toad has a reputation as the “Psychedelic Toad!”

Its venom is illegally harvested and used as a hallucinogenic drug, and it is even classified as a controlled substance. It is also dangerous to most animals, and large dogs who accidentally eat them have been known to be paralyzed or even die from the poison.

Colorado River Toad Range Map:

Though not widespread, they have a large population throughout the desert and mountains of the southwest United States. You can recognize its call, which lasts under a second and has been compared to the whistle of a ferryboat.

In the United States, laws and regulations have been implemented to prevent the use of the Colorado River Toad’s venom as a drug. They can’t be moved across state lines, and if a person is found in possession of one with the intent to use its venom as a drug, they can be arrested or fined. Never handle this toad with your bare hands, and keep your pets away from them as well!

#30. Black Widow

Identifying Characteristics:

• Females are 6 to 19 mm long—shiny black with a distinctive red hourglass-shaped mark. A row of red spots is sometimes visible above.
• Males are half the size of females.
• Bristles on their hind legs, which they use to cover their prey with silk once it has been trapped.

Black Widows are the most venomous spiders in the United States!

In addition, this dangerous animal is one of the most recognizable spiders in the world. Almost everyone can recognize the red-shaped hourglass mark that appears on the females.

But even though they have highly toxic venom, 15 times stronger than a rattlesnake, they are not aggressive. Black Widows only bite when in danger or if their web is disturbed. They RARELY bite humans.

But, if you are one of the few unlucky people who are bitten, you should go to the hospital immediately. The venom is dangerous, as it affects your nervous system.

Deaths to healthy adults are VERY rare, but the neurotoxic venom can be fatal to small children if untreated.

Only adult females are dangerous to humans, as males are too small to pierce our skin.

The best places to look for these venomous spiders in the United States include overhanging ledges, woodpiles, under benches or stones, near entrances to abandoned rodent burrows, or around outbuildings. Inside your home, they can be found in dimly lit locations, such as dark corners, closets, or other cluttered areas. They don’t like moisture and prefer dry areas.

#31. Brown Recluse

Identifying Characteristics:

• Both sexes are 6 – 10 mm long.
• Yellowish to grayish brown. The head is often darker, usually with faint or distinct violin-shaped marks.
• Long legs.
• Also known as Violin Spider or Fiddle Back.

These venomous spiders can be found in the United States both outdoors AND indoors.

Yes, you can’t even escape them in your house, as Brown Recluses commonly live inside homes and buildings. They prefer dimly lit locations, like dark corners in a basement, closets, cluttered areas, or even inside your shoe or bed! 

Brown Recluse Range Map

Many people regard the Brown Recluse as more dangerous than the Black Widow.

That’s because everyone knows exactly what a Black Widow looks like with their distinctive red-hourglass shape on an entirely black body.

But a Brown Recluse looks like many other common types of house spiders. So instead of treating them with caution and respect, most people don’t even know they are looking at a dangerous venomous spider!

Luckily, Brown Recluse bites are rare, and these spiders only bite if provoked.

But unfortunately, since they live indoors, bites sometimes occur when someone accidentally steps or rolls on them while sleeping. The bite is painless, so you may not even know you have been bitten until later.

Bites can result in lesions, nausea, fever, and wounds that are slow to heal, becoming necrotic and sometimes causing secondary infections. Necrosis (death of cells) sets in quickly, resulting in an excruciating and gruesome “flesh-rotting” wound.

#32. Mosquitos

If you’re anything like me, you’re well acquainted with mosquitos.

These small, blood-eating flies are a nuisance all over the world. But what I didn’t know until recently is that there are actually over 3,600 different species of mosquito!

All the different types of mosquitos have a few things in common, including their single set of wings, elongated mouth, and the annoying habit of sucking blood.

But some species don’t bother humans, while others can be dangerous carriers of different types of disease. For example, some mosquito species are vectors for diseases like malaria, dengue fever, Zika, or West Nile Virus. Other species target pets or livestock, transmitting heartworm, Equine Encephalitis, and other diseases that affect animals. 

There are three main ways to prevent mosquitos from spreading disease:

• Eradicating or controlling the population of mosquitos prevents the spread of diseases at the source.

• Vaccines or prophylactic drugs can help curb infection rates, even if people or animals are still bitten by mosquitos.

• Mosquito netting, insecticides, and bug repellents can be used to keep mosquitos away and prevent bites in the short term.

All of these options work quite well, but using them all in tandem is the best way to stay safe from mosquito-borne illness. Practically, always make sure you wear insect repellent when you hike or camp!

#33. Ticks

Identifying Characteristics:

• Ticks are round insects with an elongated “snout-like” mouth and eight legs.
• Their coloring varies from brown to black, sometimes with reddish or white markings.
• These insects drink blood, and their bodies swell as they become full.

Ticks are some of the most widespread blood-eating insects in the United States.

Some ticks live indoors, but they’re most commonly found in grassy or wooded areas with water nearby. They wait on tall grasses for a host to pass, then jump onto the host and attach to start feeding.

Different types of Ticks prefer different hosts, but in general, a Tick will attach itself to any blood source, including domestic dogs, livestock, stray pets, birds, and, of course, humans. Interestingly, a few species can live for years without a source of blood.

These insects are considered dangerous animals because they can spread disease when pierce your skin. Although there isn’t a hard and fast rule, it’s accepted that the longer a tick is attached, the higher the risk of infection. So if you notice a tick on your skin, you should remove it with a tick key, wash the area with soap and water, and contact your doctor. 

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Some of the most common tick-borne diseases are:

• Rocky Mountain Spotted Fever: high fever, chills, muscle aches, headaches, and rash
• Tularemia: bite infection, fever, chills, and swollen lymph nodes
• Tick Paralysis: respiratory distress, paralysis
• Powassan Virus: brain infection (encephalopathy) leading to death
• Lyme Disease: Fatigue, headache, joint and muscle pain, fever, and chills
• Alpha-gal: delayed allergic reaction to meat, including anaphylaxis
• Various canine and equine diseases, which can harm pets and livestock

#34. Kissing Bugs

Kissing Bugs get their name from the (very creepy) habit of biting near thevictims’ms’ mouths. These insects carry the parasite Trypanosoma cruzi, which causes Chagas disease. Although it’s treatable in its early stages, if a T. cruzi infection is left untreated, it can cause a chronic, lifelong illness.

Initial symptoms of this disease include fever, fatigue, body aches, headache, rash, loss of appetite, diarrhea, and vomiting. In its long-term phase, reported symptoms are cardiac complications such as enlarged heart and heart failure, and gastrointestinal symptoms like difficulty swallowing, digestive issues, and the inability to eat solid food.

With symptoms like these, it’s easy to see why Kissing Bugs are considered a dangerous animal! One of the easiest ways to prevent Kissing Bug bites is to use mosquito netting and insect repellent while you’re in areas where these insects live. Additionally, make sure to follow up with a doctor if you notice bites or sores around your mouth and nose. 

#35. Africanized Bee

• A. m. scutellata x Apis mellifera

This dangerous animal is nicknamed the Killer Bee for good reason!

Africanized Bees are a hybrid species created by breeding European Honey Bees with West African Honey Bees. These insects are much more aggressive than their ancestors, making them more dangerous and less desirable for beekeeping. 

They are more territorial, swarm more frequently, and chase threats for further distances than other honey bee species. Unfortunately, they also live in much larger colonies than other honey bees, which only adds to the threat. 

Many people assume that Africanized Honey Bees have more potent venom than other types of honey bees, because more people die from their stings. However, the actual cause of these deaths is the swarming nature of the “killer bee,” meaning many bees sting at once and cause a deadly reaction. It’s important to remember that even these aggressive bees won’t seek out humans to sting; they will only attack if they see you as a threat.

To avoid danger, be extra cautious when you clear brush or clean up debris. If you find a beehive or nest, slowly move away and call a beekeeper or animal control. Unless you have experience, you don’t want to try and take care of these bees alone!

#36. Common Desert Centipede

The Common Desert Centipede is a pale orangey-brown color with lateral black stripes. However, it can have several different colorations, giving rise to another common name, the Multicolored Centipede. Its head and tail tip are usually more orange than the rest of the body.

The rare color morphs can be exceptional, though. For example, individuals may be pale blue with purple stripes and turquoise legs, despite being the same species.

They may be pretty, but it’s best to avoid this centipede in the United States.

The bite of the Common Desert Centipede is one of the most painful bites possible from an arthropod. Much worse than a wasp sting, it has been compared to the Bullet Ant Sting and will almost certainly send you to the emergency room. The venom spreads after the initial bite, and the pain worsens until you seek treatment.

This centipede is unlikely to kill you, but it can cause localized tissue necrosis around the wound. Some call it the most painful bite in the world. Despite its ill effects, it can still be useful in medical applications. Elements of the venom have antimicrobial properties against many diseases that can make humans sick, including E. coli.

#37. Tarantula Hawks

• Genus: Pepsis & Hemipepsis

Depending on your point of view, Tarantula Hawks are either terrifying or incredible. For instance, if you have arachnophobia, you’ll probably thank these giant wasps because their favorite food is tarantulas! On the other hand, if you’re afraid of bees, you should probably avert your eyes. 

Tarantula Hawks are aptly named because of their food preference and extremely large size. These wasps are commonly 3.5 inches (9 cm) long, making them the largest wasps. They also have enormous stingers that are impossible for almost all predators to consume. Their long legs, hooked feet, and large, rust-red wings only add to their dangerous appearance. 

Although stings from these wasps aren’t typically lethal, they are excruciatingly painful. They’re considered one of the most painful stings in the world, second only to the famous Bullet Ant. If you’re stung by a Tarantula Hawk, you can expect immediate, blinding pain that lasts for up to five minutes. Most people who have been stung describe the sensation as so intense that they couldn’t do anything but scream until it subsided.

In addition to the pain, some people may experience severe allergic reactions or anaphylaxis to the Tarantula Hawk’s venom. Luckily, they are usually very docile and will only sting if heavily provoked. Steer clear!

#38. Fire Ants

Fire Ants are a group of stinging ants made up of over 200 individual species. In general, they have a few things in common. First, all Fire Ants are varying shades of red, from dark reddish brown to bright crimson. They all sting, with varying levels of pain resulting. Finally, they’re all more aggressive than other ant species. 

These insects form large colonies topped with hills and usually eat insects, plants, and flowers. However, if their nests are disturbed, they won’t hesitate to swarm and sting large animals, including humans. Unfortunately, their stings are quite painful and are often compared to the feeling of being burnt by an open flame.

In addition to the initial pain of a Fire Ant sting, you also have to be concerned about allergic reactions or anaphylaxis. Plus, the stings often blister or form raised pustules that can burst and become infected. It should go without saying that the best course of action is to avoid Fire Ants, but if you are stung, you should seek medical treatment.

#39. Wasps, including Yellowjackets and Hornets

Wasps, or what most people in the United States call Yellow Jackets or Hornets, are species of insects that have a reputation for being angry, aggressive, and targeting humans. So it’s no wonder they’re considered dangerous animals! These stinging insects can be a nuisance and a real pain (literally). 

Remember, though wasps are aggressive and can be unwelcome picnic guests, they’re still important pollinators. So, unless they’re nesting in a dangerous area or preventing you from enjoying your yard, try to give them space to continue “bee-ing” themselves. 😉

Here are a few key ways to tell wasps apart from bees:

A. What they eat: Wasps are carnivorous hunters and scavengers. While they’re attracted to sweet things like flower nectar and your open soda can, they want to eat the OTHER insects that are also looking for a meal.

B. How they act: Generally, wasps like yellow jackets and hornets are much more aggressive than most types of bees. They will buzz close to humans and even ram into us, looking for a meal or marking their territory. If they feel threatened or provoked, they will sting as well. This can cause an anaphylactic or allergic reaction in some people.

C. Their appearance: Wasps have some specific traits that make them easily identifiable compared to most bees. Instead of hair, they have spines on their legs, which are long and often bright yellow. In addition, their bodies are elongated, and the space between their thorax and abdomen is narrowed, giving them the look of a tiny waist.

#40. Striped Bark Scorpion

Identifying Characteristics:

• Colors vary from yellowish to light tan in adults; younger individuals are darker.
• Both have two broad black bands along the tops of their abdomens.

Striped Bark Scorpions are perfectly camouflaged to protect them from predators and to help them hunt for prey.

This scorpion lives in various habitats, including the desert, deciduous and coniferous forests, and temperate grasslands. Look for them in crevices under rocks, vegetation, old rural structures like sheds, and even houses during the day.

Striped Bark Scorpion Range Map

Many people come into contact with the Striped Bark Scorpion every year. Unfortunately, these encounters often happen when someone is barefoot, which can lead to being stung. If you live in the same area as this scorpion, check your shoes before putting them on!

Thankfully, their sting is rarely deadly, but it does cause pain and swelling. Even if you have a mild sting, you should still see a doctor to make sure you don’t get an infection.

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Which of these dangerous animals in the United States have you seen?

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