I keep my 5 babies in a one gallon tank. I would prefer having them in something larger, but there is no money to be spent for another couple months. Since they are around 3-5 inches, there is a lot of room for them all still. I won't be keeping them all, so there is still a ton of room left for the two I will be keeping. My (almost) one year olds haven't even hit 9 inches and would fit in it, and still be able to stretch out fine. They don't need a huge area, to live. For other species of garters, they should probably have a larger space, since they aren't born being 1-3 inches long.