Tell them apart
Common Watersnake vs. Florida Cottonmouth
It matters: the Florida Cottonmouth is venomous, while the Common Watersnake is harmless.
Common Watersnake
Nerodia sipedon
Harmless
- Family
- Colubridae
- Group
- Watersnake
- Size
- Heavy-bodied, 2–4.5 ft.
- Identify
- Heavy banded or blotched body, round pupils, and a narrow head — unlike the cottonmouth's broad, blocky head.
Florida Cottonmouth
Agkistrodon conanti
Venomous
- Family
- Viperidae
- Group
- Cottonmouth
- Size
- Usually 2–4 ft, heavy-bodied.
- Identify
- Heavy body, triangular head, vertical pupils, and a heat-sensing pit between each eye and nostril.
How to tell them apart
Harmless watersnakes are constantly mistaken for the venomous cottonmouth. Watersnakes have round heads and round pupils and flee into the water.
Never rely on a single feature to judge a live snake. If you cannot positively identify it, keep your distance. Informational only.