Rat snakes are members – along with kingsnakes, milk snakes, vine snakes and indigo snakes – of the subfamily Colubrinae of the family Colubridae. They are medium to large constrictors and are found throughout much of the Northern Hemisphere. They feed primarily on rodents. Many species make attractive and docile pets and one, the corn snake, is one of the most popular reptile pets in the world. Like all snakes, they can be defensive when approached too closely, handled, or restrained. However, rat snake bites are not dangerous to humans. Like nearly all colubrids, rat snakes pose no threat to humans. Rat snakes were long believed to be completely nonvenomous, but recent studies have shown that some Old World species do possess small amounts of venom, though the amount is negligible relative to humans.

Kingsnakes are colubrid New World members of the genus Lampropeltis, which includes 26 species. Among these, about 45 subspecies are recognized. They are nonvenomous and ophiophagous in diet.