We had 4 hens. We lost our oldest lady. She was given to us 3 years ago so I'm not sure how old she was. Over the years she would occasionally be missing feathers on her back and I always thought it was from molting because she wasn't picking at the area and didn't seem bothered. Then yesterday when I brought out a treat for everyone, she wasn't interested. Took a closer look and saw her rear-end feathers were all missing and tons of flies were picking at her. She also looked a little unsteady while walking. I then set up a cage for her in the garage so flies couldn't get to her. I had planned on giving her a bath after dinner. When I returned to her a few hours later she had passed Also, 2 of my other chickens refuse to go in their coop at night. This started about 2 months ago. Every night I have to carry them to their coop. I've read that mites might be getting to them. I checked the coop for mites at night with a white cloth. I didn't find any sign of them. The 3rd chicken tends to go broody so I wonder if she scaring the other 2... Does it sound like we have mites that caused my old lady to die and maybe that's why the others won't go in their coop? Or did she die from old age??