Hatchlings range in size from 9-14 inches (22-36 cm); adults are generally 2.5 to 5 feet 76-152 cm) in length; most are in the 3-4 foot (91-122 cm) range. The average life span of these snakes is 10 years, although one was documented to be 21 years old.
In the wild, hatchlings feed largely on small lizards and tree frogs, while adults feed on small rodents and birds, killing their prey by constriction. In captivity, hatchlings Corns can easily be started on pinkie mice (1-2 day old), quickly moving up the prey scale, to fuzzies, crews and small adult mice. Both hatchlings and adults can be fed prekilled rodents.
Growth
Many people believe that a reptile will not grow any larger that its tank. THIS IS NOT TRUE! The reptile keeps growing and will become miserable, and probably ill, if the proper tank size is not provided. The only way to "stunt" a reptile's is to not feed it enough; assuming you do not want a dead reptile, this is not something you should do. Always find out the adult size of an animal before you buy it. Note that many pet stores intentionally stunt a reptile's growth; they find it's easier to sell a cute young reptile to someone who does not know what they are looking at than an older, bigger animal. Always inquire how old the animal is, when it was acquired, etc. Be a knowledgeable consumer, not an impulse buyer.
Enclosure
Corns must be housed in at least a 20 gallon tank. The tank must have a secure top. A determined snake can push against screen or glass until it finds an opening big enough for its head; where its head goes, so goes its body. Some snakes will constantly rub their nose against the screened top of the tank in an effort to find a way out. The resulting abrasions should be treated with an antiseptic and antibiotic ointment. The furnishings in the enclosure should then be evaluated to provide a more natural environment.
Substrate
With corn snakes, there are a couple of different substrates that can be used, such as pine chips (not cedar chips, are toxic), indoor/outdoor carpeting and "Astroturf". If you use the carpeting or Astroturf, you must wash it then let it dry thoroughly before it can be used in the tank again; have two pieces on hand which can be rotated. The snakes will often burrow under the chips or carpet/turf, so don't be surprised if they are not always in view. If you use pine or aspen shavings or cypress mulch, the urine and feces can be scooped out with a cat litter scoop, with fresh chips added as needed. Be sure to remove soiled substrate as soon as possible; urine-soaked material become a breeding ground for bacteria and fungus. If you use this type of substrate you will have to place your snake in a secure area to feed it; you do not want it to ingest any chips.
Temperature
An undertank heat pad is placed under one-half of the tank; this leaves one side cooler so that your snake can regulate its body temperature as needed. A heating pad made for people can be purchased at any drug store; set it at medium or low depending upon the ambient air temperature. To maintain health, corn snakes must be kept at 75-85 F, the higher temperature being necessary to digest its food. Temperatures can fall to the lower range at night. To easily monitor temperature, inexpensive aquarium self-stick thermometers can be purchased and applied about an inch above the bottom of the tank on the warm side.
Hot rocks should never be used; they fluctuate too much, and too many reptiles suffer severe ventral burns.
Feeding
An active snake will happily eat every 10 days or so. They will eat, and should only be fed, killed prey. A snake who is not hungry when live prey is introduced into the enclosure often finds itself becoming the meal, especially if the prey is a rat.
Water
A bowl of fresh water must always be available at all times. It will be used for drinking and sometimes for bathing. If the snake defecates in it, the bowl must be cleaned and disinfected immediately.
Provide a Hiding Place
A hide box of some sort should be provided, and an interesting branch for climbing and resting. Branches collected from the wild will need to be debugged by soaking first in chlorine/water solution, then rinsed thoroughly, soaked in clean water, then left to dry in the sun. No special lighting is required.