Corn snake

Identification

The corn snake is a slender, medium-sized constrictor with an orange to reddish-brown back crossed by 27–40 reddish, black-edged blotches². Its belly has a bold black-and-white checkerboard pattern, which may explain the name, as it looks like the kernels of Indian corn^6,7. A spear-shaped mark runs forward from the neck to a point between the eyes, and a black-edged reddish stripe runs from the eye past the jaw onto the neck^2,4. The underside of the tail has two black stripes, the scales are glossy and weakly keeled, and the pupil is round^3,6.

Snakes from the coastal plain are usually bright orange, those from the Piedmont and uplands are darker and duller, and young snakes are browner or greyer². Adults usually measure about 0.9–1.2 m², and the record length is 1.88 m³.

Distribution

The corn snake lives in the south-eastern United States, from southern New Jersey south through the Carolinas to the Florida Keys, and west to eastern Louisiana². It is found in every county of mainland Florida and throughout the Keys³. In Tennessee it lives mainly in the southern two-thirds of East Tennessee and the state’s south-western corner⁵.

A 2002 genetic study split the old, wider species into three: the name Pantherophis guttatus now covers populations east of the Mississippi River, while the western forms are Slowinski’s corn snake (P. slowinskii) and the Great Plains rat snake (P. emoryi)^4,8. The Reptile Database follows this arrangement¹. Introduced populations live on several Caribbean islands, including the Bahamas, Grand Cayman and St Thomas⁷, and one has been reported from Bahia in Brazil¹.

Habitat

Corn snakes use many habitats, including open pine woodland such as longleaf pine sandhills, abandoned fields, hardwood hammocks and the edges of farmland². In Florida they also live in swamps and are often found in suburban neighbourhoods³. They are drawn to barns, sheds and old buildings, where rodents are plentiful^2,5. By day they hide under logs, loose bark and debris, or in burrows².

Behaviour

Corn snakes are mainly active at dawn and dusk, and become more active at night in hot weather². They climb well but spend more time on the ground than their close relatives the rat snakes, and they often travel through rodent burrows^2,5. They are often seen crossing roads on humid nights².

When approached, a corn snake usually flees or keeps still³. If cornered, it draws its front body into an S-shape, strikes and rapidly vibrates its tail tip, which can make a buzzing sound in dry leaves³.

Diet

Corn snakes kill larger prey by constriction but often swallow small prey alive³. Young snakes eat mostly cold-blooded prey such as frogs and lizards, while adults switch to rodents and birds². They also eat bird eggs and are efficient predators of quail and songbird nests². Tennessee’s wildlife agency lists small rodents as the main food, with treefrogs, lizards, birds and bats also taken⁵.

Reproduction

Corn snakes mate in spring and lay their eggs in early summer^2,6. A clutch usually holds 10–20 eggs, although clutches of 3 to about 40 have been recorded^2,3,6. The eggs are laid in rotting logs, burrows, sawdust piles or other damp, sheltered spots, and the parents give no care^2,6. They hatch after about 60 days, and the young are 20–30 cm long². Young corn snakes mature in two to three years².

Venom and medical significance

The corn snake has no venom and is not dangerous to people or pets^3,6. Like other harmless snakes, it will bite to defend itself, and almost all bites happen when someone deliberately handles or harasses it³. Its main medical relevance is that it is often mistaken for the venomous copperhead^2,4.

Conservation

The corn snake is listed as Least Concern on the IUCN Red List (assessed in 2015 and published in 2016)⁹. It adapts well to farmland and suburbs, but habitat loss, fragmentation, road deaths and collection for the pet trade can harm local populations². Many are killed by people who mistake them for copperheads^2,7. It is protected in Georgia and South Carolina².

Similar species

Corn snakes are often mistaken for the venomous copperhead (Agkistrodon contortrix), which has hourglass-shaped crossbands that are wide on the sides and narrow across the back, and lacks the corn snake’s bold checkerboard belly^4,7,10.

The corn snake is itself a kind of rat snake, sometimes called the red rat snake, but young grey and eastern rat snakes lack its spear-shaped mark between the eyes^3,5,6,8. Adult rat snakes are larger, usually 1.07–1.83 m long, and are mostly black above across most of their range, or striped in peninsular Florida^3,11. Milk snakes and mole kingsnakes have a short eye-jaw stripe that stops at the mouth, and no stripes under the tail^4,5.

These differences are not a safe basis for handling any snake. Keep your distance from every snake you cannot identify.

In captivity

The corn snake is a very popular pet and is the snake species most commonly bred in the pet trade⁷. Pet corn snakes usually live 10–15 years¹², and some have lived up to 23 years in human care⁷. The RSPCA advises a secure vivarium that prevents escape and lets the snake stretch out fully, with a warm basking area at one end and a cooler area at the other so the snake can control its body temperature¹².