I have 5 hens (almost a year old), one hen (lowest in pecking order) started plucking out other hens feathers and 2 chickens let her. At first I thought she might be grooming them but now one has a bare bum and the other has a bare chest area and a thinning behind-- so I don't think this is the case. I brought the plucker into the house for a couple of days thinking that when she returned to the coop the others wouldn't tolerate her pecking at them. However, I may have made things worse. I put her in the run today and she was immediately bullied by one hen who relentlessly chased her and would not let her eat or drink. I also noticed a different hen sneaking feathers from another. It use to be so peaceful now it's like mutiny! Made me wonder if the bully hen has been keeping the plucker away from food causing her to be low in protein and in turn start eating feathers. I don't have the space or facility to separate more than one chicken. Should I take the aggressive hen in the house instead and not worry about missing feathers? I live in the SF bay area so the weather is mild. The run is around 80sqft, the coop is quite small but plenty of room to roost plus nesting box. In the cooler season I shut them in the coop at night and let them out around 7am. Their diet: all-day layena, 1 cup scratch in a.m., 1 cup B.O.S.S. in afternoon, some greens almost daily: wheat grass, kale, cabbage leaves. Thanks for any help!