about half of my 27 chickens are missing all or most of the feathers on thier butts. when it first started happening it was the feathers on thier backs, so i was sure it was one of the roosters causing it as he was mean when he mated the hens, treading, pecking, pulling at thier necks, etc..(i had seen him being violent when in the sexual act). once i got him out of the way (and into a crock pot) they started losing butt feathers. i assumed this was because the hens who were being taken care of by the now dead rooster were re-establishing the "pecking order". i'd see them chase each other around pulling butt feathers. now it has gotten to the point where half of my chickens are missing ALL the butt feathers and thier butts are getting red and swollen looking. yesterday i noticed some bloody scabs on some of the bare butts. i have seen no mites, but will inspect again with a magnifying glass tonight. so...2 questions - if it IS mites, i've heard you can dust them with sevin dust. how much do you use and how do you dust them? if it ISN'T mites, just pecking... what can i do about it? thanx a million, you gurus of chickendom.