Cool...I was wondering that as well. I was going to let the babies grow up a little by themselves in a separate bin but decided to go ahead and separate them into sexes with the "older kids." It was actually pretty cute...the older rats treated the babies like their own (grooming etc. even caught the older female 'stimulating' one of the babies to poo/pee). The babies have been following the older ones around and everyone piles on top of each other to sleep. Dammit, I'm getting too attached to these guys!![]()