I have noticed that my garters regularly follow each other around and they frequently share the same hiding spot. I think a part of is that they instinctively follow the other guy to see what goodies he/she might find. I've noticed this at feeding the most. They are very aware of each other and would rather go for the same piece of food even if there is an entire plate in front of their nose. They do seem pretty indifferent when they are apart though.