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reptile · snake
Northern Cottonmouth
Agkistrodon piscivorus — Viperidae
30–48 inches
IUCN
Least Concern
Federal (US)
None
Virginia
None
VWAP Tier
Not Listed
Habitat
Found in Virginia
How to identify
- Heavy, thick body relative to length
- Dark olive, brown, or black coloring, often with faint banding
- Broad, flat head distinct from neck
- Elliptical pupils
- White mouth interior visible when threatened
- Swims with head held high out of the water
About this species
The northern cottonmouth, also called the water moccasin, is Virginia's only venomous aquatic snake. It is found in the swamps, marshes, and slow-moving waters of the coastal plain. Despite its fearsome reputation, cottonmouths are generally reluctant to bite and typically give ample warning by opening their mouth wide to reveal the bright white interior — the source of its common name.
Often confused with
Northern Watersnake
Watersnakes have round pupils, a narrower head, and swim with their body at the water surface; cottonmouths hold their head elevated and have elliptical pupils
Brown Watersnake
Brown watersnakes have square blotches on a brown body and a distinctly narrow neck compared to a wide head; cottonmouths are heavier-bodied overall
Did you know
"Young cottonmouths have bright yellow or green tail tips which they wriggle to lure frogs and lizards — a behavior called caudal luring that they lose as they mature."
SERC rehabilitation notes SERC does not rehabilitate venomous snakes. Coastal plain only. Frequently misidentified — most 'cottonmouth' reports in Virginia are actually northern watersnakes.
Sightings & citizen science
Help document Virginia wildlife by logging your sightings on iNaturalist. Every observation builds the conservation data that researchers and rehabbers depend on.
View Northern Cottonmouth observations on iNaturalist ↗Found one injured?
If you've found an injured or displaced Northern Cottonmouth in Virginia, our triage guide walks you through what to do.