Its me again. I have another chicken issue this winter. I just went out to the coop and my Buff Orpington is missing feather around her backside. NOT directly around the vent, but her backside and back of thighs. Skin is pink, no redness, skin issues, sores, or chapping (though my bum would be chapped in this weather!) I saw no lice or mites, no lice eggs at feather bases. Is someone pulling them out? Its been a tough winter so far. I open the hen doors to let them out except on the coldest of days (0-12 degrees). We have 8 hens in an 8x6 hen house with 2 hen doors with double runs (front and back). I feed them crumble, water with vitamins, scratch for warmth, and sometimes give oatmeal mash with peanut butter and raisin or scrambled eggs. Why is my Orpington missing her bum feathers?