I have 18 hens and 2 roosters that are going on 1 year old in May. The feather picking started against the roosters last summer - minor - a few feathers off the back. During the winter it has increased and spread through the flock. One rooster gets it really bad - would be killed if I didn't remove him until healed. Other hens get back and butt feathers off. I've tried everything!! Increased protein in diet to 18%. Extra scratch and greens. Space-wise they have indoor coop and outdoor run. Have added square footage by building a second level in the coop. Blue Kote, Pine Tar. I have tried process of elimination by transferring the birds into another pen to see if there is particular offender or offenders, but am not coming up with anything definitive. Oh the breeds are: Plymouth Barred Rock, Buff Orphington, Easter Eggers, and Barnevelders. Since one rooster gets it the worst, I wonder if I eliminated him the behavior would calm down? - or would it just transfer to another. This is like a cancer. I get a balance for a bit and the behavior calms down and then starts back up even when I think I have figured out the offenders. Now that weather is nicer and they free range, I thought it would stop. NO. AAAAAGGGH! Want to get rid of the whole batch and start over. Any ideas anyone please??