● Venomous · Native to the United States

Florida cottonmouth

Agkistrodon conanti (Gloyd, 1969)

Also called water moccasin
Data updated October 2026

Florida cottonmouth with its broad head raised above dark water among fern fronds
Fig. 1 — An adult in a swamp, its head held just above the water among ferns.
Close view of a young Florida cottonmouth with a dark facial stripe and bold brown crossbands
Fig. 2 — Young snakes are boldly banded, and the dark stripe through the eye is edged in cream.

At a glance

Florida’s cottonmouth is a heavy-bodied pit viper found in every county of the state. It is not aggressive and usually stays put or gives a warning display. Its bite is dangerous and always needs emergency care.

01

Identification

Florida cottonmouths are heavy-bodied, with light and dark brown crossbands that darken with age; many old adults look almost uniformly black. A broad, dark stripe runs through the eye across a cream-colored cheek and helps hide the eye. Many have two dark vertical bars on the tip of the snout. The pupils are vertical, and there is a heat-sensing pit between eye and nostril. Young snakes are much paler, with a sulfur-yellow tail tip.

  1. 01Dark facial mask. A broad dark stripe from the eye to the back of the jaw, on a cream cheek.
  2. 02Snout bars. Two dark vertical bars on the front of the snout in many individuals.
  3. 03Head held up. At rest it often holds its head raised off the ground, tilted upward.

Commonly confused with

In Florida, harmless watersnakes are the most frequent lookalikes. The eastern copperhead overlaps with this species only in the Panhandle.

02

Size

01 ft2 ft3 ft4 ft Typical adult · about 36 in (91 cm)

Most adults measure 30 to 48 inches (76–122 cm), and the average is close to 3 feet. The largest reach about 6 feet (180 cm).

03

Range & habitat

Cypress trees standing in still, dark swamp water
Fig. 3 — Cypress swamps and other wetlands are prime cottonmouth habitat in Florida.

The Florida cottonmouth lives throughout Florida, in every county, including many nearshore islands, Gulf islands in Levy and Franklin counties, and the Upper Keys. Outside Florida it reaches southern Georgia and southeastern Alabama.

It is a wetland snake. Most are found within about 30 feet of water, though some wander 100 feet or more away. In parts of Florida it is most common in pine flatwoods.

State guides: Florida

04

Diet & predators

Florida cottonmouths are opportunistic. They eat fish, frogs and other amphibians, snakes, small mammals, birds and eggs, and small turtles; even baby alligators are taken. They often wait in one spot for long periods for prey to come close. A cottonmouth found in Everglades National Park in 2015 held a scarlet snake, the first record of that prey for the species.

Feeds on

  • Fish
  • Frogs and other amphibians
  • Snakes, including scarlet snakes
  • Small mammals, birds and eggs

05

Behavior & seasons

Florida cottonmouth coiled on a road at night with its head raised
Fig. 4 — An adult resting on a road at night, head raised at an angle.

Cottonmouths hunt mainly at night. They are not aggressive and avoid contact with people and pets. Most bites happen when a snake is handled, harassed or accidentally stepped on. They can bite underwater, despite a common belief that they cannot.

06

Reproduction

Florida cottonmouths give birth to live young in late summer and early fall. A typical litter holds 7 to 12 young, and large females may have as many as 22.

07

Conservation

The Florida cottonmouth is widespread, with records from every county in Florida, and it is not federally listed.

08 — Bite safety

If someone is bitten

Cottonmouth bites are rarely fatal, but every bite needs medical care. Call 911 or go to the nearest emergency department. For guidance, call Poison Control at 1-800-222-1222. If a pet is bitten, take it to a veterinarian right away.

This page does not give first-aid or treatment instructions. Read our safety disclaimer.

Keep reading

Sources

Data updated October 2026 · How we build these pages