I have two baby rats, about a month old, maybe a bit older. One is a white male, he has the red eyes and everything. He looks like he is going bald on his back area.... and the hair he does have is very light and thin. He does have full hair on his head, face, and sides. Is this normal? I have not seen him scratching or anything, and he has the same behavior as usual. Him and his sibling do play fight often, is she maybe accidentally pulling his hair out while they play? Or is this normal since he has lighter fur and just needs his adult coat to grow in? Any advice you can offer is greatly appreciated. thanks.