Bullying

Question
I have two female rats that I've chosen to seperate due to them fighting and one of them was picking on the other by making her head bald. I chose to only put them out to play together and for a while it meant her hair grew back but now its happening again. Should I completely seperate the both of them? I hate the thought of one them being bullyed by the other.

Answer
Are they actually arguing or is the one female just overgrooming the other? Overgrooming is usually caused by boredom and just offering the rats some enrichment toys may help distract her from barbering her roommate. If it's actually them arguing/fighting/bullying, yes, they should probably be separated -- but it doesn't sound like any fighting to me, just excessive grooming.