The cottonmouth, or water moccasin, is a dark-colored, heavy-bodied snake that can grow to an average of 2-4 feet in length. Juvenile cottonmouths are a brown or tan color with darker, reddish brown crossbands containing many speckles down the back. Juveniles also have bright yellow tail tips. As cottonmouths age, the color becomes darker, so that adults show only a trace of the original pattern or are uniformly dark. Cottonmouths have a broad head and a dark stripe that runs through the eye, and there is a deep facial pit between the eye and the nostril.
Cottonmouths are often confused with the more common, nonvenomous water snakes. They can be distinguished by the vertical pupil, presence of a facial pit, and when viewed from above, the eyes of cottonmouths are not visible because of an overhanging brow ridge. Water snakes have round pupils, no facial pit, and when viewed from above, have visible eyes.
Cottonmouths are found throughout Florida in wet areas, including streams, lakes, marshes, swamps, retention ponds, and roadside ditches, although they can wander far from water.
While cottonmouths are not necessarily aggressive, they are venomous and should be avoided when encountered.