We have a coop, its a "hoop coop" made from pvc and moveable, plus a night time "safety coop", lol. Predators did not get my poor hens... it was some sort of illness. They didn't seem ill, but one day a hen died. We looked her over and she had some crusty skin, like psoriasis looking. Nothing else appeared wrong. The other chickens seemed fine. We searched for mites and found a few so we put some DE into their sand box, and into the bottom of the night time coop. Weeks later another chicken died. Same thing, no symptoms, but she had crusty skin on some parts of her. Then a while later, another chicken. And so on. I have searched for pictures that may tell what the crusty skin was, but so far haven't found anything. I am planning to post in the forums here...Hi and Welcome to BYC! I'm so sorry about your flock! Was it a predator that got them, or was it an illness? Do you have a coop and run for them?