OK I can't figure out why my rats will not breed. I've had the colony set up since early July and nothing. I have 1 male to 3 females. I have the rack system with the mixing tubs and all, but no luck. I've tried separating one female out to reduce crowding but that hasn't worked either. I can't figure out what I'm doing wrong. Aren't rodents supposed to be the horniest of all mammals? You'd think I was trying to breed pandas here.....