Atlantic Salt Marsh Snake
Found only in Florida, the Atlantic Salt Marsh Snake is threatened by waterfront development that eats into its habitat.
The copperhead is the most common venomous snake in the Eastern United States.
Brown Tree Snake
The brown tree snake is venomous, but its venom is not very dangerous to adults. However, the snake has wrecked havoc on the island of Guam, where it is an invasive species. Brown tree snakes have destroyed Guam's native bird population and often cause power outages by climbing on electrical wires.
Bullsnakes are sometimes mistaken for rattlesnakes, but they're nonvenomous. In fact, the snakes are important for controlling the rodent population in areas such as Nebraska.
California Glossy Snake
This harmless serpent lives in inland California, where it burrows in the ground by day and hunts rodents and small birds by night.
Also known as timber rattlesnakes, these rattlers live in the eastern United States. They can deliver a venomous bite, but usually strike out only when threatened.
Copperheads are pit vipers, but their venom is relatively weak. Still, it's a good idea to avoid copperhead bites: They can cause extensive scarring, tissue death and pain.
"Red on yellow, kill a fellow..." Coral snakes pack a nasty bite, inspiring folk rhymes to help people tell them apart from their non-venomous cousins. Red bands touching yellow bands are a sign of venom in coral snakes, but only in North American species. On other continents, venomous coral snakes come in many colors and patterns.
Hog-nosed snakes are known for two things: Their upturned snouts and their tendency to play possum. When threatened, the snakes will often hiss and pretend to strike. If that fails, they roll over on their backs and play dead.
These harmless snakes range across the southern United States.
Night Snake, New Mexico
The night snake lives in dry areas of western North America. Easily mistaken for a rattlesnake, the reptile is only dangerous to rodents and other prey.