Sounds like you have a female going into heat, I never thought I would have problems out of mine either, but when they go into heat it changes everything, I always keep the one going into heat up in a different room lock up because of the boys, diapered and bellyband & gated, I don't trust those little suckers at all, but it helped with my girls, they will growl once in awhile but never have the big fights until the heat starts.
