Cottonmouths (Agkistrodon piscivorus) are poisonous snakes in the Southeast. Cottonmouths get their name from the white interior of their mouths when threatened.
Cottonmouths and copperheads are pit vipers, an Oregon herpetologist told Live Science. Cottonmouths have heat-sensing facial pits between their eyes and nose, Viernum explained
These pits can detect minute temperature variations so the snake can attack the source of heat, often prey. Cottonmouths only bite when provoked.
The International Union for Conservation of Nature says cottonmouths live in southeastern Virginia, Florida, central Texas, southern Illinois, and Indiana.
Snakes hunt in water or on land. According to the University of Michigan's Animal Diversity Web, they devour fish, small animals, birds, amphibians, and reptiles, including smaller water moccasins.
Cottonmouths kill with a single poisonous bite, then wrap around and swallow their prey whole.