10 Most Dangerous Animals in the USA

venomous and poisonous snake

Razor sharp fangs, intimidating howls and unrivaled lethality – some of the world’s deadliest animals can be found right in the U.S. Brush up on these dangerous animals before your next adventure, or you may find yourself in a world of hurt!

1. Grizzly Bears

close-up photo of a grizzly bear

Grizzlies are North American brown bears famous for their dominant temperament and daunting size. The colossal creature has humped shoulders and a strikingly-high forehead. Its brown fur is usually silver-tipped, giving the grizzly its namesake grizzled effect.

An adult grizzly towers eight feet high – much taller than the average human – and weighs about 900 lbs. The Alaskan grizzly bear, or the Kodiak bear, is even more intimidating, as it’s the largest living land carnivore, on par with the Polar bear. The Kodiak may reach a weight of 1500 lbs. and grow 10 feet tall.

The Kodiak is lumbering, but other grizzlies are agile and can run incredibly fast – up to 30 mph. Grizzlies sometimes attack humans without evident provocation, but females with cubs are the most aggressive.

Its immense power and razor fangs and claws put it at the top of its league, making it a true apex predator. You will mostly find it roaming the wilds of Alaska.

2. American Alligators

American alligator

The American alligator is the apex predator of the marshlands in the southern United States. It is striking when young – black with yellow banding – then brownish when adult, reaching a phenomenal and petrifying 19 feet.

Unfortunately, just as the rest of the predators here, the main threat to it is man. People have hunted the American alligator for its skin and its young has been sold in droves as pets.

Because of this, the American alligator evaporated from many corners of America where it once abounded.

Finally, after winning legal protection from hunters, the American Alligator made a dazzling comeback. Typically, the beast eats fish, small mammals and birds.

If it is feeling pumped, however, it may devour prey on the scale of deer or cattle.

Unnervingly, both sexes of American Alligator hiss. The male may unleash a roar that carries across massive distances. Beware of the females, in particular, as they may be twitchy when guarding their eggs.

3. Snakes

Adventurers beware: the U.S. is home to some of the deadliest snakes around, so equip yourself with the knowledge to defend against them.

The menacing look of a snake comes naturally – the smooth scaly body, forked tongue and giant fangs are designed to do more than just intimidate.

Most snakes, however, are not that dangerous, and if you leave them alone they won’t harm you. If you tread on or inadvertently corner one, however, you may be in trouble.

Here are the 4 most dangerous snakes in the U.S. Avoid these formidable predators at all costs.

Mojave Rattlesnake


The Mojave rattlesnake is a venomous pit viper that lurks on bare grasslands in the southwestern U.S. The adult Mojave rattlesnake stretches about three feet long and has a distinctive appearance: it has a triangular head, narrow neck and short, black and white banded tail ending in a rattle.

Knowing how to identify a Mojave rattlesnake is a vital skill, as its venom presents a mortal hazard. The lethal species varies in color from gray and pale brown to olive. Like so many dangerous snakes, it is deceptively intriguing. A chain of brown diamonds with light centers and white edges extends along its back.

Some Mojave rattlesnakes pack the tissue-damaging hemotoxins typical of rattlesnakes. Others pack paralyzing neurotoxins that are sneakily destructive, causing no pain until acute respiratory distress kicks in.

New World Coral Snake


The New World coral snake, also known as the “true coral snake,” is an eye-catching specimen, but do not be deceived. Like the Mojave rattlesnake, it is a highly dangerous snake.

Widespread in the southern U.S., the New World coral snake has a narrow head, sleek body and long, pointed tail. Its creepy “snout” is rounded and its eyes are tiny.

Its most distinctive attribute is the narrow yellow rings set between black and red rings. “Red next to yellow can kill a fellow, red next to black and you’re all right Jack,” is a popular jingle that separates the snake from its harmless mimics.

Inclined to burrow, the New World coral snake passes most of its time tucked away in animal tunnels, hollow logs and under rocks. Sometimes, it can be found hanging out in stone ruins. Remember to be aware of these danger zones the next time you set off exploring.

Theoretically, it is in the market for small snakes and lizards, but you do not want to test that theory because the New World coral snake has a tetchy temperament. If accidentally touched, it will strike in a flash. Any bite it inflicts should be taken seriously because it can be fatal.



The moccasin – or water moccasin – is a dark, heavily-built, venomous North American snake, filed as part of the viper family. Semiaquatic, the moccasin hovers in these settings: riverbanks, swamps and sluggish waterways of the southeastern Gulf and Mississippi Valley states.

The adult moccasin usually grows to up to four feet long, but can reach a terrifying six feet long. The moccasin’s color ranges from dull brown to olive or black, with wide black, jagged bands. It also as a distinct flat-topped, triangular head set atop a slender neck that looks small relative to its surprisingly chunky body.

If you find yourself in a tight space with a creature resembling a moccasin, don’t panic. Take a second to check out the eyes. If the pupils are round, it is a harmless water snake, probably more scared of you than you are of it. If the pupils are “vertical” on the other hand, it is a venomous moccasin.

When angry or spooked, the moccasin shakes its tail, throws its head back and gapes, baring its pair of membrane-covered fangs. Even more unnervingly, the open mouth and throat are strikingly white. Hence the reptile’s nickname, cottonmouth.

The cottonmouth can bite underwater. The venom that the reptile releases is acutely toxic – a bite can be fatal to a human victim, making it another dangerous snake that you should never mess with.

Ever gone head-to-head with one of the most dangerous snakes in the U.S.? Tell us your story in the comments below.

Burmese Python


In the Florida Everglades, Burmese pythons can be found scrapping with alligators to sit at the top of the swamp’s food chain. Pythons are also taking out other hefty animals that get in their way.

In 2011, a 16-foot python was found resting after devouring an entire deer. Invasive pythons now maraud the Everglades – they own the area – and they are moving towards the Florida Keys and elsewhere up north.

The snakes were unleashed by irresponsible pet owners into the Everglades, which cover about 4,000 square miles of Florida. They are on the march and on the up because they combine lethality with fertility. A female python can lay 100 eggs, which is tough on the ecosystem.

Since the Burmese python’s takeover, there has been an extremely large decrease in raccoons, opossums, and bobcats. Marsh and cottontail rabbits and foxes have also been alarmingly absent.

The Burmese python sports sharp rearward-pointing teeth that seize its prey, and is one of the largest snake species on earth.

4. Gray Wolf

gray wolf

Also called the timber wolf, the gray wolf may look less imposing than the grizzly, but it is still a force to be reckoned with.

The largest wild member of the Canidae family, male gray wolves may weigh in at just under 100 lbs. The wolf resembles a German shepherd, only with a bigger head, narrower chest, longer legs, and larger paws.

The gray wolf is an alpha predator wherever it roams. While grizzly bears are surprisingly big on berries, gray wolves have an alarming penchant for livestock and, occasionally, humans.

Wolves are bouncing back from a threatened conservation status in the Great Lakes, the northern Rockies, and the Southwestern United States.

5. Great White Shark


Few are surprised to see this name on a list of most dangerous animals in the USA. You have to hand it to the great white shark. Few other creatures on the planet, except saltwater crocodiles, are so terrifying.

The great white shark may be North America’s most commanding alpha predator because it operates in the ocean – a location that automatically puts humans at a disadvantage.

The most feared shark in the ocean, the great white is sometimes called the white death. It grows up to 20 feet long and can weigh almost two tons. The great white is incredibly formidable – capable of short, high-speed pursuits and even breaching -launching itself clear from the water.

In addition, the great white packs large, triangular, blade-like teeth that are serrated along the sides. The super-predator also boasts powerful jaws and the ability to sense vibrations and electrical impulses.

It can also smell, taste, hear and see extremely well. The great white can burst toward prey at speeds of up to 31 mph. Its diet includes seals and even whales.

Despite its negative reputation, sharks rarely attack people. When one does, it is usually because it mistook a diver, swimmer or surfer for a seal or other prey.

One place to see Great Whites is near the Farallon Islands off San Francisco. One company runs a tour [http://www.greatwhiteadventures.com/]. The usual deal with great white experiences is you get dunked in a cage while your tour operator obligingly dangles tasty, shark-friendly morsels to draw the animals over.

You probably won’t want to go swimming in great white shark-infested beaches for obvious reasons.

If there is any upside to shark attacks from an American perspective, it’s that they mostly seem to happen off the coast of Australia.


Arachnophobia is a serious condition, especially for adventurers, but the most dangerous spiders in the U.S. are enough reason to want to avoid arachnids altogether.

Arachnophobia, the fear of spiders, is one of the most common phobias in the world, and with reason. An adventurer can be mortally wounded by a spider if he tangles with the wrong species.

Here are the most dangerous spiders in the US.

Black Widow


The black widow spider is the common name of any of the species of poisonous North American spiders. The black widow is notorious for the toxicity of its venom to humans.

Its bite unleashes a tiny, yet potent, dose of a neurotoxin that sparks local pain, swelling, and – if you get unlucky – respiratory distress and death.

The widow’s venom is one of the most potent in the animal kingdom, relative to body size. If bitten by several widows at once, your survival chances are slim to zero. The black widow is easily identified – jet-black in color, with characteristic red markings on the underside of its abdomen.

The black widow gets its name from its mating ritual – the much bigger female widow eats the male after mating, probably to suck up the vital nutrients needed for egg-laying.

Black widows occur all over North America, but mostly in the northern, western, and southern regions of the continent.

Brown Recluse


Also referred to as the violin spider, the brown recluse can be found in the western and southern U.S. Its body stretches about a quarter of an inch. On the front half of its body, it sports a dark, violin-shaped design, the “neck” of which is formed by a striking furrow on the midline of its back, and the spider’s six eyes are set in two rows.

The brown recluse’s venom is extremely deadly – it destroys the walls of blood vessels near the site of the bite, sometimes causing a giant skin ulcer. The wound, which may require several months to heal, can kill. Despite its name, the brown recluse has broadened its range into parts of the northern U.S. and beyond.

It rides along with packages in the mail and in vehicles, and may even lurk in your clothing. Its natural home is caves, rodent burrows, and other shielded settings. In buildings, it usually occupies quiet spots like attics, storage areas, and wall or ceiling voids.

Hobo Spider


The hobo spider resembles the brown recluse, but with hairier legs. Again, like a recluse, the hobo’s venom can cause tissue to die at and around the bite site. The wounds can take months to heal and leave permanent scars. Meantime, one of the easiest to identify symptoms of a hobo spider bite is a thumping and persistent headache that medication can’t eradicate.

The hobo spider builds a trampoline-like, funnel-shaped structure of silk sheeting and lurks at the small end of the funnel. Then, it waits for prey to wander into its web.

The hobo spider is the leading cause of serious envenomation in the northwestern U.S. Since its introduction from Europe into the Seattle, Washington area in the 1930s, the hobo has been rapidly expanding its reach. It is common around Salt Lake City, Utah.

Yellow Sac Spider


Pale yellow or whitish, the yellow sac spider sits in silk tubes during the daytime and comes out to hunt at night. Its habitat is surprisingly domestic. It favors houses – specifically the top of walls and ceilings. It also hovers outdoors on foliage.

The “draglines” it leaves while hunting are one of the most common spiderwebs that you may eradicate with a broom or vacuum cleaner. People sometimes unwittingly brush up against them in the dark, to their regret.

The yellow sac spider’s bite is toxic – the venom contains the substance cytotoxin, which can destroy cells much like the venom of a brown recluse.

The common symptoms of a yellow sac spider bite are a stinging sensation, followed by redness and swelling. Sometimes, blisters form and burst. The yellow sac hunts for food – usually insects – at night.

Brazilian Wandering Spider


The Brazilian wandering spider is the most venomous spider on earth. Stretching up to five inches across, the highly aggressive creature has a territorial outlook. It is not native to North America but turns up through hitching rides. It is sometimes called the banana spider because it appears in bunches of the fruit.

When rattled, the Brazilian wandering spider stands itself up on its back legs, showing its striped arms. In severe bite cases, its potent neuro-toxic venom can trigger shock, paralysis, even death, if medical treatment is not received quickly.

You can identify the Brazilian wandering spider by the scarlet hairs covering its fangs. The Guinness Book of World Records ranks the Brazilian wandering spider as the most poisonous spider and the one responsible for the most human deaths.

7. Mountain Lions

Mountain lions are also known as pumas, cougars, and panthers. A beast of many names, the mountain lion dominates the small cat species as the biggest one of the bunch. What’s more, mountain lions reign supreme over North America. They are ferocious and stealthy predators, which makes them some of the most dangerous animals in the USA.

An average mountain lion won’t see you or any other human as a tasty snack. Still, encountering one is not a pleasant affair. If they see you as a threat, you better run. Females weigh between 60 and 140 pounds, while the males can reach an astonishing weight of 220 pounds. So, appearing as a threat to one of them doesn’t sound like the best idea.

Mountain lions are amazing predators. They will stalk their prey for miles before they attack it from behind, delivering a swift killer blow. Although they prefer deer, sheep, and other mammals, they will eat and attack anything if they are desperate enough.

In fact, the one human life they take on average each year is probably due to the fact that an unsuspecting hiker wandered far enough into the mountains of Western United States to encounter a hungry and desperate mountain lion.

Mountain lions have only had 88 fatalities under their belt in the past century or so. Still, that doesn’t mean they haven’t earned their spot on our list of the most dangerous animals in the USA.

8. Wild Boar

Wild Boar

If you don’t think that wild boars are scary, think again. This animal was the ultimate downfall of Robert Baratheon. For those who haven’t been bitten by the Game of Thrones bug, and don’t get that reference, here are some statistics.

Wild boars have a yearly death toll of 10 people in the United States alone. That makes them more dangerous than the mountain lion.

Wild boars don’t inspire horror in the hearts of hikers as much as some other animals do. But they should! They are ferocious and, well, wild. While some other members of the animal kingdom will move out of your way or simply growl threateningly, a boar will chase you aggressively.

In nature, wild boars are far from the friendly (if crude) Pumbaa. Disney had us all fooled!

Both destructive and combative, wild boars will wreak havoc if they think they are threatened.

The situation becomes that much worse if they believe their younglings are threatened or if you happen to have the bad luck of running into one during mating season.

9. Killer Bees

a killer bee

Small yet deadly, killer bees are the stuff of nightmares. They may be tiny, but they never come to the party alone. If they feel threatened, they will attack, much like the wild boar.

However, unlike the boar, there are usually thousands of them. Imagine several hundred or thousands of bees swarming you relentlessly.

You may think you’re safe since you’re not allergic to bees and generally don’t have the habit of poking around a hive. Well, think again.

These Africanized bees take the concept of personal space to the next level and consider the area around their colony to be their property. If they catch you trespassing, they may chase you for as far as a quarter of a mile. What’s more, if you really agitate them, you may have an entire hive on your hands to deal with.

When push comes to shove, it won’t matter if you’re allergic to bees or not. Even though it isn’t particularly potent, the killer bee venom can make your kidneys shut down if enough of them sting you at once.

That’s how the killer bees kill over 100 people in the USA every year. So their place as some of the most dangerous animals in the USA is well earned.

10. Arizona Bark Scorpion

Arizona Bark Scorpion

Arizonans really have it rough. Not only do they have to deal with the heat and the fact that they live in a desert, but they also have frequent house guests that look terrifying and repulsive.

Arizona bark scorpions often visit the homes of many Arizona residents because they don’t burrow, so your home may seem like the perfect hiding space to them. What’s more, these creatures of horror are nocturnal, and they hunt at night.

However, their eyesight is quite terrible (much like their appearance). Pair those two facts together, and you’ll get a clear conclusion — it’s really easy to stumble upon an Arizona bark scorpion and get accidentally stung.

The scorpion shoots first and asks questions never. The sting is instinctual, which means that any encounter with this little animal kingdom resident can be extremely painful. Although not deadly, the stings are quite agonizing.

Still, only small children, ill or older people, are at risk of meeting their Maker through one of these creatures of pure nightmares.

11. Deer and Dogs

It’s a devastating surprise that the most dangerous animals in the USA aren’t those with sharp claws and talons, or those sporting a pair of killer venomous fangs. Quite the contrary — the animals with the highest death tolls are deer and dogs.

Going from cute to deadly in the blink of an eye, deer and dogs kill between 40 and 200 people every year in the United States.


Now, this may come as quite a shock, but deer actually have one of the highest death tolls in the United States. It won’t pounce or stalk you, but a deer may jump in front of your vehicle, thus making you crash.

Deer are the reason for 200 annual untimely deaths, and they cause even more injuries, so it’s entirely possible that deer are, in fact, the most dangerous animals in the USA. They crash into vehicles or make people swerve off the road so often that there’s even an official police code for it — DVC, or deer-vehicle collision.

It seems as though the deer haven’t yet adapted to the fact that the forests, meadows, and pastures their ancestors roamed are now highways and roads full of deadly four-wheeled beasts. When faced with that, instead of treading carefully, the deer simply brave on ahead, which is the reason for so many DVCs.

Still, don’t think that the deer will always be cute and cuddly if you happen to meet them outside of a highway. More often than not, you’ll spook the deer, and it will run away.

However, during the mating season, a particularly persistent male may attack you. Bambi’s dad looks majestically adorable, sure. But don’t forget it’s bigger and heavier than you, and it can cause real damage with its horns.


The most common house pet is also one of the most dangerous animals in the USA. Coincidence? Probably not. Although we see dogs as members of our family, they bite around 4.5 million people every year. What’s more, they have a substantial annual death toll of approximately 26 people.

Of course, that doesn’t mean that dogs are more vicious than sharks. But, let’s be honest, what are your chances of ever encountering a shark? Pretty slim, right? And yet, you see Cujo’s cousins around every street corner.

So, in the game of odds, you’re more likely to be hurt (or killed) by a dog than a shark.

But our cuddly buddies aren’t inherently violent or bloodthirsty. They certainly don’t have the same reputation as wild boars!

But because of the sheer number of them in our vicinity, they happen to hold the title of some of the most dangerous animals in the USA.

Although adorable, they are still animals, and playing with them or making them feel threatened may be your downfall.

About the Author

CM Burns
CM Burns
CM Burns has been a music video director, a cameraman for Nat Geo, has recorded ancient Tibetan chants in India and swum with whales in Baja, California. Currently living in the Philippines you will find him anywhere Adventure happens.
CM Burns
CM Burns
CM Burns has been a music video director, a cameraman for Nat Geo, has recorded ancient Tibetan chants in India and swum with whales in Baja, California. Currently living in the Philippines you will find him anywhere Adventure happens.
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