βΉ Compare two snakes
Northern Cottonmouth vs Plain-bellied Watersnake
Tap a part to see it on both. Tap it again to turn it off.
Melanie Gaddy, no rights reserved
Northern Cottonmouth
Agkistrodon piscivorus
Venomous(c) dhasdf, some rights reserved (CC BY)
Plain-bellied Watersnake
Nerodia erythrogaster
Non-venomousThe quick way to tell
Look down at the head from above. You can see the Plain-bellied Watersnake's eyes, and its pupils are round. The Northern Cottonmouth's eyes are hidden from above by a brow ridge, and its pupils are cat-like vertical slits.
Eyes β
This settles it
Vertical slit pupil; heat-sensing pit between eye and nostril.
Round pupils; eyes clearly visible when you look down on the head.
Head
Blocky, heavy brow, dark mask through each eye, pale snout.
Fairly large eyes, easy to see from above; lips often yellowish or orange like the belly.
Pattern
Dark olive to nearly black, with faint wide bands clearest on young snakes.
Adults mostly plain above; young have dark crossbands near the head that turn into blotches down the body.
Pits
A deep heat-sensing pit on each side of the face, between the eye and the nostril.
None. There is no pit between the eye and the nostril.
Tail
Thick-based; young have a yellow tail tip.
Plain tapering tail with no rattle; the underside is unmarked like the belly.
What it does
Coils, vibrates its tail and gapes to show a white mouth lining.
Flees if it can; bites hard and releases musk if cornered or grabbed.
Where it lives
Southeast from southeastern Virginia through the Carolinas, northern Georgia and Alabama, west to central Texas and Oklahoma, and up the Mississippi valley to southern Illinois, Missouri and southeastern Kansas.
Southeastern and central US from Delaware and southeastern Virginia south to the Florida Panhandle, west through the Mississippi Valley to Kansas, Oklahoma, Texas and the Pecos River in New Mexico; small scattered northern populations in Iowa, Illinois, Indiana, Ohio, Kentucky and southern Michigan. Also northern Mexico.