I have a 1 1/2 year old female cat and while she is grooming herself she appears to stop and nibble or bite at her fur. We've caught her pulling out fur before (due to stress most likely) and I'm not sure if this biting is normal or her pulling out fur again. I've seen her bite her fur a lot and she appears to be over the pulling out of fur but I can't figure out why she is nibbling at herself.