Reptiles · Squamata · Viperidae

Cottonmouth

Agkistrodon piscivorus

Least Concern

The species is abundant and widely distributed; it faces no significant short-term risk. See full glossary

The cottonmouth is a venomous snake, a pit viper, that lives in the south-eastern United States. Adults are large and capable of delivering a painful and potentially fatal bite. If confronted, they defend themselves by coiling and showing their fangs. Although their aggressiveness has been exaggerated, on rare occasions territorial males will approach intruders aggressively. This is the only semi-aquatic pit viper in the world, and is generally found in or near water, particularly in shallow, slow-moving lakes, streams and marshes. This snake is a very good swimmer and sometimes even goes out to sea, having successfully colonised islands off the Atlantic and Gulf of Mexico coasts.

Weight

300 g – 2 kg

Size

65 cm – 1.4 m

Lifespan

20 years

Diet

Carnivore

Feeds mainly on other animals.

Activity

Nocturnal

Active mainly at night.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Easy

Temperate forestFreshwaterCarnivore Nocturnal Solitary Reptile Temperate forest Freshwater

1countries 6parks22same family

Fun facts

GeneralIt gapes to show the white lining of its mouth as a warning, which is where the name cottonmouth comes from.
It is the only semi-aquatic viper in the world: it hunts fish, frogs and other snakes under water and can stay submerged for long spells, something no other viper does as a matter of course.
Its reputation for aggression is false: a classic study deliberately trod on dozens of individuals in boots and only a minority tried to bite; most fled or merely gaped in warning.
That display of the white mouth lining is the species' most characteristic warning signal and the origin of its English name, cottonmouth.