America may seem civilized to you, as you lock your door and hop on the subway or into the car, then hang around indoors all day. When you go to the zoo, there’s a disconnect. Ferocious animals seem to be things that exist behind bars. It’s easy to forget that this very country is home to some historically human-killing animals that could totally murder you in your sleep. Depending where you sleep. (But they probably won’t.)

Here’s our list of the Top Ten Most Badass Animals Native to the USA, a little about their habits, and where in the great United States you’re likely to be ambushed by one of them.

1. Polar bears. These big, beautiful beasts employ a method called “still hunting,” in which the bear sniffs out its prey’s home, then crouches by the door until the prey emerges. Then it crushes their skull. Normally, this prey is a seal, but polar bears have also hunted hunters and campers — this guy while he was sleeping in his tent (warning: graphic). Though polar bears are listed as a vulnerable species (likely to become endangered), they are still roaming Alaska. And they don’t just want Coca Cola.

2. Rattlesnakes. Normally, rattlesnakes kill small animals, but anyone who’s been to the Southwest knows: if you hear that rattle, you’d best be moving along. And by “moving along,” I mean “running for your life.” Their hemotoxic or neurotoxic (depending on the type) venom can kill you in horrendous ways, including respiratory paralysis. Check out this story from a guy who was bitten by a rattler when he was 13. Word to the wise: if the snake’s rattle gets wet, it won’t make any sound, so watch out during the rain. Rattlesnakes have been reported in many states, but keep an extra eye out in California, Nevada, Utah, Arizona, Texas, and New Mexico. And while you’re down there, stay away from fatally poisonous water moccasins (the world’s only semi-aquatic viper) and coral snakes, too.

3. Coyotes. Just last month, according to Telegraph.co.uk, woman in Canada was mauled and killed by two coyotes, while “hiking alone on a trail in Cape Breton Highlands National Park, in Nova Scotia.” Coyotes are typically reported in the Southwest, but have also been sighted in Illinois, Wisconsin, Oregon, New Jersey, and all over New England. You can find them living in deserts, forests, plains, or even in icy regions like Alaska. Basically, these guys (and ladies) can live almost anywhere. Their diet is 90 percent mammals, which you may have noticed you are. They’ll get you on the ground, then bite/break your neck. According to Wikipedia, coyote attacks have been increasing in California since 1998.

4. Bobcats. According to the Arizona Game and Fish Department, bobcats who attack humans are typically rabid. That means attacks are less likely, but also all the more deadly. Bobcats, though just 20-24″ tall when full grown, will sometimes stalk larger animals which they can kill and repeatedly return to to eat over time. They typically catch them sleeping on the ground and bite into their neck, chest, or the base of the skull. That’s not even fair.

5. Alligators. These guys eat mostly fish, worms, and snails and stuff, but if you get to close, they’re known to attack humans. Wikipedia reports them living in “all of Florida and Louisiana, the southern parts of Georgia, Alabama and Mississippi, coastal South and North Carolina, Eastern Texas, the southeast corner of Oklahoma and the southern tip of Arkansas.” Alligators have also been found in extreme southern Missouri along the Mississippi River during the summer months.If you’re swimming and see one approaching, you’d best get the heck out of the water. Worse still, you might be mistaken — those alligators approaching could be …

6. Crocodiles. Crocodiles have pointier-shaped jaws than the alligators’ u-shaped jaws. Either way, you should probably run. Crocodiles live mainly in Florida (within the US), and are extremely dangerous to humans. Crocodiles eat mammals like you, fish and birds, and occasionally each other. While these web-footed cannibals probably won’t be able to chase you, they are extremely adept swimmers, and normally attack before their prey even sees them.

7. Bears. Kelly Ann Walz in Pennsylvania was killed last month by her own pet black bear — her Bengal tiger and African lion left her alone. Donna Munson, a 74-year-old who liked to feed bears, was killed last August. Black bears live in 41 US states, and while they’re certainly known killers, they are not as dangerous as brown bears; especially grizzlies and Kodiaks. According to Wikipedia, there are about 32,500 brown bears in the United States, mostly in Alaska and along the Rocky Mountains. Brown bears confront you like they’d confront other bears; by growling and huffing. Then, they bite your jaw to keep you from biting back. That’s only if they feel like taking their time; they can actually just crush a human head with a single bite. Weirdly, you’re more likely to be attacked if you run — I’d love to meet anyone who stood still after being growled at by a bear.

8. Wolves. Unprovoked attacks by non-rabid wolves are rare, but do you know where they tend to attack? The crotch. According to Answers.com, “Wolves will typically attempt to disable large prey by tearing at the haunches and perineum, causing massive bleeding and loss of coordination.” They drag small prey (including children!) to a secluded spot and feast on the abdominal cavity — sometimes before they prey is even dead. Be extra wary in Northern Minnesota, the Rockies, and New Mexico.

9. Cougars. While older women in search of younger men can certainly be dangerous, I’m referring to the North American Puma concolor couguar, also known as pumas, mountain lions, or panthers. Check out a list of fatal cougar attacks in North America here. While they are mostly found in the western United States, cougars have been reportedly expanding eastward, and in 2008, a cougar migrated from South Dakota to Wisconsin, and then right down into Chicago, where it was killed by a cop in an alley. When cougars attack humans, they attempt to get their teeth between your vertabrae and into your spinal cord. I shudder just thinking about it.

10. Brown recluse spiders. Perhaps they’re not “animals,” but no list of wild things in the United States would be complete without this silent killer. Also known as violin spiders, brown recluses live mostly in the southern states — check out a map here — in terribly familiar places: anywhere dark and normally undisturbed, like a woodshed, a basement, garages, closets and even under beds. Bites are rare, but if one accidentally gets into your clothes or bedding and is pressed against your skin, you’re in trouble. The bites can lead to necrosis, which is essentially your flesh rotting right off of your body.

If you’re heading on a camping or hiking trip, keep what these animals can do to you in mind, and don’t go provoking any of the fauna. By behaving respectfully towards nature, you can greatly lessen your chances of being attacked by an animal — but if you see a brown recluse spider, call pest control.