so update on the rat intro, the got their second meeting cause they all started playing in their own cages thought it would be ok to have them see each other again, they played for a while then machiatto got nipped for trying to hump my biggest one, now they are all playing but he is standing in the corner and wont move all the other rats come over and see him but he has his defensive posture up even to the other 2 babies he lives with but once the big ones are gone he calms down and plays again