Both rough and smooth green snakes prey primarily upon insects. Both species eat arthropods, such as spiders, grasshoppers, caterpillars and worms. However, the diet of the smooth green snake almost exclusively comprises invertebrates, whereas the rough green snake takes small frogs as well.
Both species subdue and kill prey by striking rather than constricting. Both snakes are native to the eastern United States, with smooth green snakes occupying a northerly range and rough green snakes occurring farther south.
Rough and smooth green snakes are both colubrids but, despite both receiving the nickname of grass snake, the species belong to different genera. They are similar in appearance and coloration. Rough green snakes have noticeably keeled scales, giving them a rough appearance, while the scales of smooth green snakes have no keel.
Smooth green snakes inhabit meadows, prairies and open forests, whereas rough green snakes prefer more densely vegetated areas near water. Rough green snakes spend a great deal of time in trees; smooth green snakes tend to hunt on the ground. Both rough and smooth green snakes are relatively common in their respective ranges and are not species of concern, although there is some population decline due to habitat loss and road fatality. As both species are largely insectivorous, they sometimes suffer from the excessive use of pesticides in parts of their ranges.