So I've had my two rat boys, Darwin and Virgil, for about two months now, and they have always gotten along great. I got Virgil about a week after Darwin, and Virgil is younger than Darwin, but I don't know the exact ages of either. Virgil is much friendlier than Darwin, who is still pretty scared of me. They have always been great with each other, though. They snuggle and sleep together sometimes, but not always. They play fight, but I've never seen anything that looked like actual fighting until today, until when I came home from work today I picked Virgil up and hes got a wound on his manly bits. First of all I'm worried about the possibility of infection. But also, is this kind of aggression common in male rats? They are sleeping together now, is it possible that some play fighting just got out of hand? Should I be worried?