A pair of eastern garter snakes of average size may be maintained in a 20 to 30 gallon capacity terrarium. The substrate may be of fallen oak and maple leaves, folded newspaper, several thicknesses of paper towels, aspen shavings or cypress shavings. Hiding areas and visual barriers in the form of small hollow logs, securely anchored rocks or driftwood, or plastic hide-boxes are accepted cage furniture. A water bowl sufficiently large for the garter snakes to both drink and soak is provided. Garter snakes will often stool in their water. The water must be kept fresh and clean.
Daytime illumination should be provided. During cold weather a small undertank heater may be run. Although these hardy snakes are not adversely affected by normal room temperatures, the garter snakes may coil and bask on cool days on a flat rock atop the heater if one is provided. The temperature on the surface of the rock should be in the 90s Fahrenheit while the rest of the tank is about 80 degrees in the summer and 74 degrees in the winter. According to the wants of their owner, garter snakes may be kept active through the months of winter or they may be hibernated for 90 days. Although they seldom do so, some garter snakes may choose to miss a meal during the cooler winter months. Their diet should be adjusted according to their needs.
Eastern garter snakes eat worms (nightcrawlers are best), frogs, toads, minnows and salamanders. Some may also accept small lab mice (especially of the pinky size). To stimulate a garter snake’s appetite for small mice, the rodents may be scented by rubbing them gently with a minnow or a frog. Garter snakes give birth to live young and the neonates usually eat as readily as the adults.
Although a clutch usually contains from 5 to 40 babies, large females have given birth to more than 100 babies. A heavily gravid female may refuse food for several days or even several weeks before the young are born.
Neonates are from 6½ to 9 inches in length.