Housing
Providing a proper cage for a garter snake is second only to feeding in the amount of misunderstanding out there. The two most common mistakes that beginning garter snake keepers make is to provide a cage that is too big — I once saw someone write that they thought a 70-gallon tank was a good size for a baby snake — or too wet: while garter snakes are frequently found near water, they’re definitely not aquatic.
In general, a garter snake needs a cage that is clean, dry and escape-proof, has the right furniture, and is the right size. Here’s how to give it to your snake.
Size of Cage
The cage should be neither too large nor too small. Too small, and the snake can’t get enough exercise and its health will suffer. Too large, and the snake will feel exposed and insecure. A good guideline is to make sure that the length plus width of the cage is somewhat larger than the total length of the snake. (For example, a snake up to 90 cm long could live in a tank that is 60 cm long and 30 cm wide.)
A baby garter snake’s cage should be no larger than five gallons, and in general, a garter snake less than a year old can live comfortably in a five-gallon tank. An adult male about 60 cm (two feet) long will do well in a 15-gallon tank, and a full-grown female or a breeding pair should be all right in a 25-gallon tank. More room is certainly better within reason, and you’ll need more room if you’re using a planted terrarium instead of basic caging, but it’s very unlikely that a single garter snake will ever need anything more than a 35-gallon tank.
Preventing Escapes
Snakes are very good at escaping their cages; they can crawl through openings that seem too small for them. For that reason the cage must be abso-lutely escape-proof. Lids should be securely attached and fit tightly: snakes are strong enough to push them off otherwise. Any mesh or grille in the lid should be small enough: if a snake can work its way in past its eyes, it can get all the way out.
Glass aquariums should have screen lids with tabs that fit under the plastic rim of the cage, or snap-on grilles (so long as the snake is big enough that it can’t get between the grilles). Baby snakes in a five-gallon cage should probably have a screen lid. Plastic “Critter Keeper” or “Desert Den” cages work well generally, so long as the snake isn’t too small to get through the circular holes for electrical cables. And the herper’s standby for smaller snakes — Rubbermaids with air holes melted in the sides and lids with a soldering iron — will also work for small single snakes so long as the melted holes aren’t too big for the snake to get through.
Cage Furniture
To feel secure, garter snakes need a place to hide. This should be reasonably solid and relatively small: the snake should be able to curl up tightly within it, and if it can touch the sides of its hiding place when it’s curled up, so much the better. Formed plastic boxes that fulfill this requirement are available in pet stores, as are hollow half-logs. You can make your own boxes out of cardboard, but bear in mind that they will get soiled quickly.
Despite the fact that garter snakes are often found near water in the wild, they should not be kept in semi-aquatic conditions. A garter snake’s cage should be kept dry; a water dish large enough for the snake to curl up in is enough. Blister disease can result from too-damp conditions. However, newborn snakes can be prone to dessication (drying out). A humidity box may be provided: this is simply a hidebox containing some dampened sphagnum moss. It may help keep the rest of the cage drier if this box has a bottom to it.
Substrate and Cleaning
Substrate is what you put on the bottom of the cage. Many different kinds of substrate are possible: everything from a planted terrarium to paper towels or butcher’s paper. Other popular substrates include wood shavings (aspen is best, pine is probably all right, but never use cedar), cypress mulch, bark nuggets, or indoor/outdoor carpet.
Planted, naturalistic terrariums may be pretty, but a simpler cage is easier to clean. Garter snakes defecate frequently, and unless you change or clean a garter snake’s cage frequently, the cage will smell quite ripe in short order. It therefore makes sense to make the cage easy to clean! I recommend keeping them on paper towels, which can be replaced cheaply and quickly when soiled.
You shouldn’t have to change the cage more than once a week. More snakes in a cage will make it messier faster, of course, and a fish- and worm-based diet is messier and smellier than a mouse diet — either of these circumstances will necessitate more frequent changes.
If you use paper towels, it’s enough to replace them when soiled and rinse off the glass where the snakes have soiled it. If you use shavings, mulch or bark, pick out the urea and feces when you can, then change the cage completely every two to three months or so. Clean the cage thoroughly, using detergent or bleach, or both, every once in a while.
Heat and Light
Snakes need to be a little warmer than room temperature. This is especially true in an air-conditioned home. But they don’t like it uniformly warm, either, and it’s actually more dangerous to the snake if it’s too hot than if it’s too cold.
The ideal temperature for most snakes is in the 25-30°C range (about 75-85°F), but it’s important that the snake have the option of warming up and cooling off when it chooses. Create a temperature gradient by only heating one side of the cage.
You can use a heating pad under-neath one side of the cage, or an incandescent or reflector bulb above it. You can use a commercial reptile heating pad or an ordinary electric blanket, which is less expensive, turned to the lowest setting. fluorescent bulbs generate little to no heat. Buy a stick-on thermometer to monitor temperatures. As long as it’s above 22°C on the cold end and below 30°C on the warm end, you’re fine. Temperatures above 33-34°C are potentially dangerous.
Never, ever use “hot rocks” — these plastic rock heaters that are placed inside a cage. They may be dangerous to the snake and are of limited utility: the air needs to be warm, and a cold snake wrapping around a warm rock heater may burn itself.
Garter snakes do not appear to need full-spectrum lighting, though some keepers disagree.
Housing Together
Whether snakes should be housed together or singly is one of the most controversial subjects in amateur herpetoculture. Some keepers argue that the risks inherent in keeping snakes together are too great: you can’t monitor who eats how much and which snake is getting sick; if one snake gets sick, they both get sick; one snake can become dominant over the other and stress it out; there are risks of food fights and even cannibalism.
Others would argue that such risks can be minimized through careful observation: some snakes may not do well together, but others may do just fine. And certainly no snakes should be put in the same cage together without a quarantine period. New arrivals should be kept away from other snakes for a month or two and observed to see if any contagious health problems present themselves.
I don’t think it’s necessarily wrong to keep two snakes together, so long as both of them have checked out as healthy, both are from the same species (and it’s not a cannibalistic species; see below), they both seem to get along, and they’re fed separately (see below). In other words, keeping them together requires more observation and more attentiveness on the keeper’s part than simply keeping every snake one to a cage and forgetting about them. But closer observation and more attention are definitely not bad things!
In any event, garter snakes seem to be somewhat more gregarious than other species: they’re frequently found together in the wild. This is more than can be said for some other commonly kept species, and I suspect that much of the advice to keep snakes separately is based on keepers’ experiences with those other, more solitary species.
The garter snake breeder Phil Blais has noticed that baby garter snakes in particular seem calmer when housed collectively, and my own experience bears out his observations: a young garter housed singly seems more nervous than it was when it had cagemates. So at least in that case it is not only all right to house garters together, but even beneficial.
Obviously a larger cage will be needed if a few snakes are kept together, but there are also more serious things to watch out for.
With some garter snake species, there is a risk of cannibalism, and they should be housed individually. This is especially true of the Western Terrestrial Garter Snake (Thamnophis elegans), the most commonly kept subspecies of which are the Wandering Garter Snake (T. e. vagrans) and the Coast Garter Snake (T. e. terrestris). There have been many reports of Wandering Garter Snakes that ate their cagemates. While some have kept this species collectively with no trouble at all, play it safe and keep no more than one per cage. Cannibalism has also been reported in Checkered Garter Snakes (Thamnophis marcianus) and occasionally with Common Garter Snakes (Thamnophis sirtalis). The risk with common garters is probably quite small, and I keep mine collectively, but it has been known to happen, so consider yourself warned.
Food fights are a serious concern when feeding garter snakes, and it's likely that most reports of cannibalism are as a result of accidents happening during feeding. Garter snakes are very enthusiastic feeders and are attracted to motion. If you’re feeding them together in the same cage, one snake may be attracted to the other snake's food, and may grab the other end and start swallowing. One may keep going and swallow the other if you don't intercede. So, unless you’re prepared to deal with food fights (and I don’t recommend it), it's best to feed them separately. Have one or more small holding cage to feed them in, away from the other one(s).
A Gathering of Garter Snakes
Snakes of the United States and Canada
