The most common venomous snakes in the U.S. are pit vipers. Pit vipers have triangular heads, elliptic (slit-shaped) pupils, and fangs that are folded against the upper jaw while the snake is resting. The fangs rotate down and forward when the snake bites. The snake's name comes from the depression, or pit, midway between the eye and nostril on either side of the head. This pit is a special organ that senses temperature, helping the snake locate its prey. There are 3 main groups in this family: rattlesnakes, copperheads, and water moccasins (also called cottonmouths). Maine, Alaska, and Hawaii are the only states that do have at least 1 native species of venomous snake.

There may be small marks or wounds, redness, and swelling in the area of the bite. The area may also be painful. A person who has been bitten may also have numbness, tingling, nausea and vomiting, blurred vision, and trouble breathing.

All venomous snakes are able to inject poison from birth and should be treated as dangerous. The venom of a small or immature snake may be even more concentrated than that of larger ones. A dead snake can bite for up to an hour after death from reflex.

If you know what the snake looked like, it may help to figure out if it was venomous. How many times the snake bit and how the bites felt also can help identify the snake. That information also can indicate the amount of venom that may have been injected. It is also important to remember such symptoms as numbness, nausea, or tingling around the mouth. You may also have a metallic taste in the mouth, muscle cramps, trouble breathing, and dizziness. None or all of these symptoms may occur. Get medical care as soon as possible. Call 911 or your local emergency medical services.

All of these things can help someone who is bitten.

Many old-fashioned remedies for snakebite exist. Be careful, because some of them may cause harm.

If you are in a rocky area or near a wood pile, protect yourself by wearing boots, long pants, and thick gloves.

Try to remember what the snake looked like if you saw it. Also note the symptoms that happened after the bite to report to medical staff.

The best advice when you see a snake is to leave it alone. Don't pick it up, try to get a closer look at it, or kill it. When hiking, stay on trails or paths. Be careful where you place your feet and hands, particularly around rocks and wood debris.