Corn Snake

The corn snake, or red rat snake, is a North American species of rat snake that subdue their small prey with constriction. The name “corn snake” comes from the fact that they have a maize-like pattern on their bellies and because they were found in corn fields. The Oxford English Dictionary cites this usage as far back as 1676. Corn snakes are found throughout the southeastern and central United States. Their docile nature, reluctance to bite, moderate adult size 1.2–1.8 metres (3.9–5.9 ft), attractive pattern, and comparatively simple care make them popular pet snakes. In the wild, they usually live around 15–20 years, but may live as long as 23 years in captivity.

Like most rat snakes, corn snakes are non-venomous.

Natural habitat

Wild Corn Snakes prefer habitats such as overgrown fields, forest openings, trees, palmetto flatwoods and abandoned or seldom-used buildings and farms, from sea level to as high as 6,000 feet. Typically, these snakes remain on the ground, but can ascend trees, cliffs and other elevated surfaces. They can be found in the southeastern United States ranging from New Jersey to the Florida keys and as far west as Texas.

In colder regions, snakes hibernate during winter. However, in the more temperate climate along the coast they shelter in rock crevices and logs during cold weather, and come out on warm days to soak up the heat of the sun, a process known as brumation. During cold weather, snakes are less active and therefore hunt less.

Diet

Corn Snakes have a diet primarily consisting of rodents, mostly mice and rats. Prey is killed by constriction. They are proficient climbers and may scale trees in search of birds and bats. As litters of infant mice are difficult to find in nature, many neonate Corn Snakes are known to eat small lizards as their first meals, and anoles are the preferred choice. Some individuals retain these dietary tendencies well into adulthood.

Corn Snakes are usually fed by their owners on a diet of commercially available rodents, predominantly mice, while younger and smaller specimens may eat live or dead rat or mouse pups of various sizes. Frozen mice that have been thawed to room temperature are usually preferred, as live prey can possibly carry disease or injure the snake if it has not been raised on live prey.

Reproduction

Corn snakes usually breed shortly after the winter cooling. The male courts the female primarily with tactile and chemical cues, then everts one of his hemipenes, inserts it into the female, and ejaculates his sperm. If the female is ovulating, the eggs will be fertilized, and she will begin sequestering nutrients into the eggs, then secreting a shell.

Egg-laying occurs slightly more than a month after mating, with 12–24 eggs deposited into a warm, moist, hidden location. Once laid the adult snake abandons the eggs and does not return to them. The eggs are oblong with a leathery, flexible shell. Approximately 10 weeks after laying, the young snakes use a specialized scale called an egg tooth to slice slits in the egg shell, from which they emerge at about 5 inches in length.

As pets

The Corn Snake was one of the first snakes to be kept in captivity by people, and remains one of the most popular. Large numbers are bred annually to ensure that there is a large captive-bred population, lowering the need to collect specimens from the wild. Cohabitation is discouraged in captivity, as these are naturally solitary animals.

Hatchling Corn Snakes are often kept in a 5–10 gallon (19–38 L) aquarium or similar-sized plastic tub. As the snake grows, it requires more space. The minimum recommended size of housing for an adult is a 20 gallon (76 liter) tank. A 40 gallon (152 L) is a good recommended size and will provide the adult snake room to move. Corn Snakes become stressed in too large a cage with no hiding places. It is a good idea to use plants and many hiding spots in a large tank so that the snake will feel secure.

Since Corn Snakes, like all reptiles, cannot regulate their internal body heat, proper external heating is necessary for their health. A heat gradient from 70–75 °F (21–24 °C) on one end of the housing to 80–85 °F (26–29 °C) on the other is thought optimal to allow the snake to regulate its body temperature by moving from one part of the housing to the other, as necessary. Insufficient heat available in an enclosure at any point may lead to poor digestion, respiratory infections, and death, while excessive heat which the animal cannot escape, can cause neurological damage. Heat may be provided by a number of measures, including an under-tank heating pad (use at one end of the tank only), or one or more heat lamp(s), which should be attached to a thermostat to control temperature. Ceramic heat emitters may also be used in place of light bulbs, but if heat sources are not placed asymmetically, one part of the tank does not remain available for the animal to escape heaters.

Aspen or cypress shavings are often used to make bedding substrate, allowing the snake to burrow. Reptile carpet, newspaper, or paper towels also work. Cedar is toxic, so wood shavings containing cedar should be avoided. Feces are usually removed by spot cleaning, and periodically the tank is washed, disinfected, and bedding is replaced.

Additionally, the snake’s living area may occasionally need to be misted if the climate is very dry. This process generally occurs monthly for baby snakes, and 3–4 times per year for adults. This shedding cycle is necessary so the snake can have proper circulation. The cycle starts with a dulling of the overall color and loosening of the snake’s skin. Then the eyes turn a milky-blue color temporarily. When the eye color becomes normal again, this indicates that the actual shedding of the skin will occur within the next few days. To ensure proper shedding, one should frequently mist the tank with distilled water, or for extra help, place the snake on damp newspaper. If the snake’s skin comes off all in one piece, then this shows that they have received enough moisture. If not, one must manually remove the excess pieces of skin, especially around the eyes and tip of the tail, to prevent blindness and poor circulation.

Juveniles may be fed newborn mice every 5–7 days. Adults do well on one large mouse every two weeks but may be fed weekly. A general rule for food size is that up to 1½ the snake’s body girth is acceptable. Corn snakes also readily take a larger number of smaller meals, and a 50 centimetres (20 in) Corn Snake has been observed to swallow up to seven smaller-size “pinkie” rodent pups (less than the snake’s girth), in rapid succession, in a span of less than five minutes. Thus, as a Corn Snake grows, smaller food items are not necessarily outgrown.

As a matter of good practice, feeding of large prey and handling should be separated as much as possible in snakes. Rapidity of feeding is facilitated if the snake is handled minimally so as not to be upset, before being transferred to the feeding container. After a snake swallows, its prey must pass its thorax and lung, along to its stomach in the mid-portion of its body (ordinarily less than a minute). Handling is avoided while this happens. After feeding and swallowing has been completed, all but minimal handling is avoided to ensure proper digestion. This is usually a full 48 hours or until no lump can be seen in the snake’s belly.

If substrates such as aspen or cypress mulch are used, the snake should be fed in a separate empty container, to prevent ingestion of chunks of substrate, which may lead to internal injury. Snakes do not require live prey, and many corn snakes feed readily on pre-killed rodents which can be purchased as frozen from commercial suppliers, then completely thawed in warm water prior to feeding. The food is not required to be warm (above room temperature) for the snake to eat it, but it must be completely thawed. Feeding corn snakes thawed mice or small reptiles greatly reduces the chance of parasitic infections and disease, and also kills many of the pathogens these creatures may have once carried. Feeding snakes thawed mice or small reptiles in a separate container also can cause snakes to be more docile in nature, and as a result can usually be handled with ease. Feeding frozen rodents also completely eliminates the risk of the snake being injured during feeding, which can happen if the prey has not been constricted for a sufficient length of time or if it prey bites or scratches the snake.

Non-feeders, snakes that have refused to feed more than twice, can be enticed into feeding by having the prey item slightly warmed, either by a heat lamp or soaked in water warm to the touch a few minutes before feeding. Microwaving prey items is not advisable as they can explode. Another technique is called “braining”, where the skull of the prey item is punctured with a very clean needle and liquid from the skull exposed with forceps or tweezers. The smell of the liquid causes most snakes to feed.

Corn Snakes need a water dish and ideally will have access to clean water at all times. Corn Snakes swim well but generally do not seek water to swim in, but may well be found sitting in the water bowl. Corn snakes drink by dipping the end of their snouts in water and sucking up fluid with their cheeks. They need water every day although most people probably will not see the snake drinking.