Posted by Kelly Stinson on September 14, 2007

Q: We came upon a small snake in the road. Its head had been crushed, very recently, as it was still quite flexible. Naturally we brought it home (carefully) and took pictures of it. Could you please tell us what kind it is? We are pretty sure it is a young rattlesnake, but we don't know what kind. The snake was found in the road between an abandoned house with an overgrown yard, and another yard with a huge section of pampas grass. We are in a rural area of southeast Texas, in northern Brazoria County near Alvin, between Houston and Galveston. Thank you so much.

Habitat: suburban/yard

State: Texas

Habitat: suburban/yard

A: This is a young Western Cottonmouth. Although Cottonmouths are related to the rattlesnakes, and are venomous, they do not develop a rattle. Even newborn rattlesnakes typically have a rattle "bud" at the tip of the tail, while this snake has a long, pointed tail.

Cottonmouths are identified by a combination of:

1. the thickness of the body: harmless water snakes are much more slender for a given length.
2. the dark crossbands; these become less apparent with age as the snake becomes darker overall. Many harmless water snakes have similar body markings.
3. a funny-looking head with the dark "mask" on the sides. Water snakes can flatten their heads when alarmed, giving a "triangular" appearance as well. The head of a cottonmouth is almost blocky in appearance, and the dark mask is usually evident.
4. If you can safely get close, Cottonmouths have elliptical pupils, while the pupils of water snakes are round.

Even without the ruler, I could tell this is a young snake because of the yellowish tip on the tail. The yellow color fades as the snake matures.

Cottonmouths are abundant in wet places throughout the Southeast. Although most individuals flee when they sense a person nearby, they will sometimes become aggressive when cornered. Often the snake will coil up and open its mouth widely to show the white inner lining. Here is an image of an adult doing this threat display I photographed in Florida:

Hope this helps.

Solon Morse ( September 14, 2007)