Belly gray-green with dark spots along the edges. Usually a pair of light spots on top of the head. Former black-soil prairies, cultivated fields, pastures, wet meadows and marshes, and vacant lots. Mates in April or May and gives birth to 5-30 young from August through early October. Does not bite as readily as the common garter snake when handled.
Common prey are earthworms, slugs, and small amphibians.
Predators include birds of prey, mammals, and other snakes. Large numbers are killed on roads each spring and autumn as they move to and from upland hibernacula.