I just bought two hairless rats and they are adorable. I was looking at them today (they are each in a tub with a bunch of girl rats, 6-7). I noticed one of them had some deep chew lacerations on his tail and feet...I figured he was getting attacked, but then i saw his body and face were fine...I wonder, is he eating himself? I mean these wounds are deep...like, gross deep.

Any thoughts on this? BTW, no other rats in either tubs have these marks...