I believe that possibly, garters may be exhibiting the "safety in numbers" technique that many prey animals, like minnows, tend to use to reduce the chance that one may be eaten by hanging around others, hoping that they get eaten instead! I dunno, it's just a guess! i know they don't enjoy one another, that's definitely not why they do it. But it must benefit them somehow and this theory is my strongest suspicion! Who knows?! They don't feel joy. I jokingly say they cuddle at times, but I hate to break it to everyone, snakes don't cuddle. They don't love us, or each other, even if they are brother and sister and have been together forever. They could not care less about each other. They simply know that food comes from us, and choosing the same hide, especially with a hide-loving snake like a ball python, often means that this is the best choice to their liking, and they are both competing for the best spot.