We are fairly new to raising chickens. We have a small flock of 6 hens. 3 RIR and 3 BO. We have begun to notice that four of the hens have bare bottoms and are starting to look somewhat thinner, and a couple have blood on them as well. They are not in molt, as they are first year hens that have only begun to lay two months ago. My husband has a suspicion that one particularly aggressive hen is pecking the other hens' bottoms. I have never heard of this before. I'm trying to determine if this is a symptom of some kind of disease, or if I in fact have a bully hen. In either case, I need advice as to how to handle it. They seem to still be laying just fine. I have not noticed any slacking off. Any help would be greatly appreciated. If the answer to this problem is obvious to everyone but me, please forgive my ignorance. I am new to all this, but until now it has been greatly enjoyable. Thank you!