Hollywood likes to portray snakes as vicious predators who terrorize humans in movies like “Snakes on a Plane” or “Anaconda.” But the reality is, snakes fear us much more than we fear them.

With more than 3,000 species worldwide, there are just 20 species of venomous snakes living in the United States. That includes 16 species of rattlesnake, two species of coral snake, one species of cottonmouth or water moccasin and one species of copperhead. Even though snakes live on every continent except Antarctica, the likelihood of encountering venomous snakes is slim.

“The ones we do come across are non-venomous,” says David Mizejewski, naturalist with the National Wildlife Federation. He offers these tips for what to do if you encounter a snake.

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If you see a snake in your yard

“Stay calm and back away. Most of the snakes you are likely to encounter are harmless snakes,” Mizejewski says.

If a snake spots you first, he will either slither away or stay completely still. “They feel threatened and don’t want to be around us,” adds Mizejewski. “Never pick them up or touch them with a stick. Just retreat.”

Your yard should be free of brush and rock piles. “If you have them on your property, make sure they are far from your home,” Mizejewski advises. “Seal off all entry points into your home.”

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How to avoid snakes when hiking

The best defense against snake encounters is to stay on the trail. Many national parks and places where dangerous snakes live have signs posted telling you never to wander off the trails. “It’s common sense,” says Mizejewski. “Snakes sometimes are seen on trails, where they come out to bask in the sun. Sticking to the trails makes it easier to spot and avoid close encounters with snakes, compared to hiking through the surrounding landscape where vegetation, logs or rocks could make spotting snakes harder.”

Snakes also can be found hiding under rocks, so never pick up a rock in areas where you know snakes live.

“If you are walking your dog and the dog sees something moving in the distance, he may try to run after it,” says Mizejewski. “Dogs should be on a leash for their own safety, and make sure your dog is close to your side on the hiking trail.”

How to tell if a snake is venomous

Some people use “venomous” and “poisonous” interchangeably, but they're not the same. “Poison is absorbed or ingested,” says Mizejewski. If you pick up a poisonous snake, like the keelback snake found in Southeast Asia, your skin absorbs the poison. Venom is injected through the snake's fangs when it bites you. (This short TED Talk video explains the difference.)

Pit viper(Photo: kurt_G/Shutterstock)

“One rule of thumb about identifying dangerous snakes,” says Mizejewski, “is that most venomous snakes have slit pupils and non-venomous ones have round pupils.”

Venomous snakes will give you a warning before they strike, giving you time to back away. When they lift up their heads and stick their forked tongues out, what they are actually doing is sniffing the air around them. Snakes don’t have noses like we do, so they use their forked tongues to smell. (They also don’t have eyelids or ears. To hear, they feel vibrations in the ground.)

If you are visiting an area where you know dangerous snakes live, read about them so you will know what they look like. If on the rare occasion you come across a dangerous snake, don’t approach it. If it’s in your yard, call animal control.

How to treat a snake bite

If on the off chance you do get bitten, call 911 and try to stay calm and still. This will slow the spread of venom if there is any, the Centers for Disease Control and Prevention (CDC) says. If possible, sit with the wound below the level of your heart and cover the area with a clean, dry bandage.

Try to remember the color and shape of the snake. This can help doctors know how to treat the bite. Do not apply a tourniquet, do not try to suck out the venom, do not cut the wound more with a knife and do not apply ice, the CDC advises. Contrary to popular belief, these methods will all do more harm than good.

Lastly, take comfort in this statistic: The number of people killed by snake bites rarely exceeds 10 people a year in the United States.

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Michele C. Hollow writes about pets and wildlife. She is an award-winning journalist who has written for The New York Times, The New York Daily News, FamilyCircle.com and other leading publications. She blogs at Pet News and Views.