Polk County Conservation


Garter snake

There are 27 species of snakes that live in Iowa. They vary in size from very small brown and red-bellied snakes that are less than a foot long to black rat snakes that grow six feet long.

Small snakes generally eat worms, slugs, and insects. While larger snakes help control populations of small mammals like mice, rats, and ground squirrels. They also eat birds and eggs if available.

Snakes hunt their prey in a variety of ways. For eggs or slow moving prey, they simply open wide and swallow the meal whole. Constrictors strike out at an animal, grab it, quickly coil around it, and squeeze it tightly until it dies. Most snakes in Iowa are constrictors.

Venomous snakes bite their prey, injecting poisonous venom through the large hollow fangs. They follow the prey until the poison takes effect and then swallow the animal whole.

Iowa has four poisonous snakes, all of which are state endangered species except the timber rattlesnake. The massasauga is known to live only in three state marshes. Timber rattlesnakes are the largest and potentially the most dangerous. They occur in eastern and southern Iowa where bits of relatively undisturbed habitat remain. The prairie rattlesnake is very rare in Iowa and is limited to the northern portions of the Loess Hills. The copperhead is found only in a tiny area of southeastern Iowa.


Iowa Herpetology - This site is designed to introduce you to the herpetology of Iowa. Contains pictures, information, and distribution of snakes in Iowa.

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Administration Office
11407 NW Jester Park Drive
Granger, IA 50109

P: (515) 323-5300
F: (515) 323-5354


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