The Red Rat Snake (Pantherophis guttatus), widely known as the corn snake, is a medium-sized, non-venomous colubrid native to the southeastern United States. Its range extends from southern New Jersey southward through Florida and westward into Louisiana and parts of eastern Texas, with isolated populations reported in Kentucky and Tennessee. The species inhabits a broad range of ecosystems, including pine flatwoods, hardwood hammocks, overgrown fields, rocky hillsides, and the edges of agricultural land. This ecological flexibility contributed to the species' long and intimate association with human settlement across its range, as early European colonists encountered the snake in and around the barns, corn cribs, and granaries where it hunted the rodents attracted to stored grain.
The common name "corn snake" has been a source of enduring etymological discussion. The most widely cited explanation holds that the name derives from the snake's frequent presence in and around corn storage buildings, where populations of mice and rats provided abundant prey. An alternative theory points to the checkered pattern on the snake's ventral scales, which bears a visual resemblance to the multicolored kernels of Indian maize. The name "Red Rat Snake" reflects the species' reddish-orange dorsal coloration and its role as a highly effective rodent predator, and this name has persisted in both popular and some scientific usage alongside the more familiar "corn snake" moniker.
The species was first formally described by the Swedish-Finnish naturalist Carl Linnaeus in 1766 as Coluber guttatus, based on specimens originating from the Carolinas. The specific epithet guttatus, meaning "spotted" or "speckled" in Latin, refers to the distinctive pattern of reddish-brown dorsal blotches bordered in black that characterizes wild-type individuals. Over the subsequent two and a half centuries, the taxonomic placement of the species shifted repeatedly as herpetologists refined their understanding of colubrid relationships. The snake was long classified in the genus Elaphe, and many older references use the name Elaphe guttata. Molecular phylogenetic analyses conducted in the late twentieth and early twenty-first centuries led to the reclassification of the North American rat snakes into the genus Pantherophis, establishing the currently accepted binomial Pantherophis guttatus.
The Red Rat Snake's range overlaps with several closely related species, including the Eastern Rat Snake (Pantherophis alleghaniensis) and the Gray Rat Snake (Pantherophis spiloides). Natural hybridization between corn snakes and other Pantherophis species has been documented in contact zones, and this interbreeding contributed to some of the taxonomic confusion that characterized earlier classification efforts. The resolution of these relationships through modern genetic techniques represents one of the more significant achievements of North American snake systematics in recent decades.