One of my older BR had been less active for the past week. I just figured she was getting older. Today found her in the coop barely able to walk. I picked her up and expected to her to have lost weight but she almost felt heavier than normal. Thought maybe she was egg bound. Noticed her backside was really messy so brought her in for a warm soak. Immediately after she went in I noticed what I thought were a bunch of tiny feathers. Put my glasses on and saw that they weren’t feathers. They were parasites. 100’s of them. . My husband immediately put her down and her remains are tightly sealed in a garbage bag. I sprayed the sink with straight bleach and it didn’t kill them. I had to wipe them out with a paper towel. I’m on my way out to clean out the whole coop and nesting boxes. Can anyone tell me what these are and how far I have to go as far as protecting my other girls?