The smooth greensnake averages 12 to 20 inches in length. It has a green back and a white or yellow-white belly. The scales are smooth.
The smooth greensnake may be found in the northern one-half of Illinois. It lives in prairies, wet meadows and vacant lots. This animal is terrestrial, rarely climbing off the ground. It is active during the day, hiding under rocks, boards or grasses at night. It overwinters in ant hills, small mammal burrows and other excavations in the ground. Mating occurs in May. The female deposits ﬁve to 15 eggs in rotten logs, decaying vegetation or leaf litter. Eggs are laid in June. Hatching occurs in August. In some areas, the female incubates the eggs within her body by basking in the sun, then she lays them in a pile of rotting plants or sawdust. This snake eats slugs, spiders, centipedes, millipedes and insects.