It is my personal belief that garters do better when housed with another garter....like Chris said, I find it actually reduces stress on the snake when another snake is around. I always try to house at least two together...although, as Stefan said, it is best to house garters of the same sex together. If you put a male and female together, you will end up with a mating situation and most likely many babies at some point. Taking care of baby garters is something that one needs to be skilled in doing....it is not an easy undertaking. Also, dealing with a gravid female can be a difficult task and stressful on the female. Another important thing to remember is that you never want to put a male and female garter of two different species together.