All of my hens (8), except one, are being feather-picked terribly. They are missing feather on their backs and on the corner of their wings ("shoulders"). The one who isn't picked is still pristine and healthy looking. Is she the culprit? They get plenty of protein. (high-protein feed, peas, occasional eggs and meat scraps, etc.) and they free range more than half of the day. Their coop/run has ample room. I have not noticed any sign of parasites. They did have mites last year, but I successfully treated that with DE and ash dusting baths for them If she is the suspected culprit, should I remove her from the flock? I have also noticed that our rooster is losing his neck feathers as well. My once gorgeous rooster is looking very scrappy now. This is very concerning also because we are in New England with a harsh winter right around the corner. HELP!