Garter snakes that have been trained to eat mice can be some of the most ravenous feeders ever seen in captivity. Some of mine, for example, have been so eager to eat mice that they’ll launch themselves towards you when you open the cage at feeding time, or grab the mouse before it even hits the substrate.
So it can be surprising when that enthusiastically feeder suddenly stops feeding in the fall. When that happens, it usually means that the snake is preparing to hibernate. And if you have the facilities for hibernation, that’s certainly an option. But for those who don’t have such facilities, or don’t know how to do it (see the Hibernation chapter of the Care section), a snake with a normally healthy appetite that suddenly stops feeding can be cause for concern, if not outright panic.
If hibernation is not an option for you, or if you want your snake to keep feeding over the winter, you may want to try changing its diet.
It appears that with some of these garter snakes, it’s not that they’ve stopped eating, it’s that they’ve stopped eating mice. When the fall comes around, they just get finickier. After a short period of time, they get less picky and start eating mice again.
I’ve noticed this only a few times in my collection — for example, an adult male Wandering Garter Snake, T. e. vagrans, in 2002 and a yearling female Checkered Garter Snake, T. m. marcianus, last fall. Most of my garter snakes have never required hibernation: they’ve been perfectly willing to keep feeding. (They got hibernated anyway if I wanted them to breed.) But these two suddenly stopped when October rolled around: the wandering garter had been eating mice for several years; as for the checkered garter, she’d been eating mice for as long as I’d had her, and I acquired her shortly after birth. In other words, these were not normally unreliable feeders.
When these snakes were offered more “natural” garter snake prey items, they did eat again. In these cases I used ocean perch fillet — snakes used to dead mice apparently don’t need the food to be moving. I think earthworms would also work, and I think I may have tried them in earlier cases: I’ve often called earthworms the garter snake’s comfort food. At that time of year, though, they may be harder to find.
After a month to six weeks and a few meals of fish or worms, they began eating mice again. It’s as though their dietary preferences narrowed as the days got shorter and the temperatures cooler — then, for whatever reason, their dietary preferences expanded again, almost as if their systems had been rebooted. (I’ve taken to calling this the “garter snake reset button,” for lack of a better term.)
I’ve only noticed this a couple of times, so if anyone else can reproduce this behaviour with garter snakes in their care, I’d be very interested to hear about it.