Over the years I have kept various sub-species of garters in small colonies. I especially like garters because you can do this and I enjoy watching them interact. When you house them together they tend to "cluster" together. On that note following are a few observations ...
I had Flames (1.1) housed together, an adult female and yearling male. When I added a second female (yearling size) to the mix, the male immediatley (almost defensively, head raised) investigated the new comer. After his initial investigation the male accepted her. The adult female checked her out too but not as aggresively as the male. Next, about a year later I added another yearling male to the mix. Exact same reaction from the established colony. Some time later, out of curiousity I decided to introduce a yearling Albino Plains (male)to the group. This time both male Flames, heads raised immediatley investigated the new comer however THIS TIME both male Flames aggressivley pursued the "stranger", chasing him around the enclosure. I removed the Plains and repeated the "experiment" a few days later with the same results. I then tried to introduce a yearling female Snow Plains and to my surprise both male Flames attempted to drive her off much the same as they did to the male Plains.
Not at all what I expected from snakes so I found this behavior very interesting 
