Cottonmouths, or water moccasins, are among the most venomous of all North American snakes. Although they rarely bite people, they are still persecuted and often killed on sight, along with many harmless water snakes, with which they are frequently confused.
This snake has a striking cotton-white lining to the mouth, which it reveals when it gapes to warn off attackers. Adults are uniformly dark olive or black; juveniles are lighter with a banded patterning.
The heavy-bodied cottonmouth spends much of its life either in or near water. It swims well, holding its head up out of the water. These semi-aquatic snakes live in damp habitats near to swamps and streams in the lowland areas of south-eastern United States. The cottonmouth is a nocturnal hunter that catches a wide range of prey, from fish and frogs to baby alligators and small mammals. The snake holds cold-blooded victims in its jaws until the venom takes its effect, but it releases warm-blooded animals after it has delivered a bite. The victim runs away but dies nearby, and the snake locates the body using its sense of smell.
The cottonmouth is an extremely dangerous species. Its venom is hemolytic - it destroys the red blood cells and coagulates the blood around the bite. The venom is actually extracted and used medically for its coagulating properties in the treatment of hemorrhagic conditions.
Female cottonmouths breed every other year and produce litters of up to 15 young which measure between 7 and 13 in (18 and 33 cm) at birth.
Distribution: South-eastern United States, including Florida, North Carolina and the Mississippi Valley and Delta.
Habitat: Swamps, streams and other wetlands.
Food: Amphibians, fish, birds, reptiles and small mammals.
Size: 51 - 190 cm (20 - 75 in).
Maturity: 3 years.
Breeding: Up to 12 young born in late summer.
Life span: Unknown.