Sounds more like mites/lice to me. Could also be you are feeding them too much protein which makes them overly itchy. You would know if they were fighting trust me. Want to see all the pics I have taken of battle scared ratties? Trust me, you would deffinately know. Force grooming is natural and helps them find out who is the leader. It can get bad, as in hair missing but not scabs. Wrinkles barbers (that's what it's called) all my girls and will pick out the hair by their ears, but never leaves scabs. I have never had a rat leave tiny scabs, so my first thought would be mites/lice.