Hello All, I have 5 barred rock Hens. I bought them about 3 months ago and they were just over a year old. When I bought the hens they all had bald butts ( no feathers). After a few weeks they all grew thier butt feathers back except one. I made a dust bath bought DE etc as I thought she may have had mites. She seemed fine always out hunting and pecking, she seemed like she was at the bottom of the pecking order in the flock but always active. I went out to let them out this morning and found her face down in the coop under her roosting bar. There was no blood anywhere that I saw, I checked her for wounds and did not see anything. There was a lot of mucus on her beak when I picked her up but other than that it looks like she died in her sleep. Any ideas of what could have caused this? I am still new to having chickens, and concerned for the rest of my flock. I might add that the coop is dry, bedding seems like it's in good shape and the ventilation is more than what is recommended. Thanks for any insight.