Our rat Mindy has gradually been loosing a patch of hair behind her ears on her neck. I noticed today she had a little bit of redness on her nose and a minor ammount of poryphin crust around her eyes. There is no scabs on either rat or the effected area on her neck. I am thinking maybe Lucy ischewing her hair to the point of loss while she grooms her. The grooming doesn't seem to be a dominance thing for them, but someone will nip to hard and it starts a heated argument (these girls cuss each other out ) Other than that they get along great, share food, build & share a nest together. Anyways Lucy is a definite grooming maniac, she even grooms my mustache... is it possible she is just giving her sister a haircut? There is no sign of skin damage and she seems completely oblivious to it.