Several of our flock have begun to look "mangy". This began with our 2 australorp hens; and looks, now, to be affecting one of our barred rocks, as well. The feathers around the neck and where the base of the tail meets the body are either missing, downy-looking, or just plain scraggly. In trying to decipher what is happening, we've ruled out molting, and haven't noticed anyone being substantially "picked on". Can anyone give me guesses as to what might be happening, here, as well as advice on what action to take, if any? Thanks so very much.