Cottonmouth

The cottonmouth is a stocky pit viper closely tied to wetlands, swamps, and slow-moving waterways across the southeastern United States. It is one of the few vipers in the world with strongly aquatic habits, often seen basking on logs at the water's edge or swimming with its head held above the surface.

Its name comes from the striking white lining of its mouth, which it displays in a wide gape when threatened—one of the more recognizable defensive displays among North American snakes.

• Heavy, muscular body with a blocky, triangular head distinct from the neck
• Coloration ranges from olive-brown to nearly black, with dark crossbands that fade with age
• Juveniles show bold reddish-brown banding and a bright yellow-green tail tip
• Vertical pupils and a facial heat-sensing pit between eye and nostril
• Often confused with harmless water snakes (Nerodia), which have rounder pupils, slimmer necks, and no heat pits

Found in swamps, marshes, drainage ditches, lakes, and slow rivers throughout the coastal plain of the southeastern US. Rarely strays far from permanent water and is absent from higher elevations and colder northern regions.

Primarily nocturnal in warm months but frequently active by day, especially in cooler weather. Feeds on fish, frogs, and other aquatic prey, along with small mammals and birds. Live-bearing, with females producing litters of young in late summer.