I have 12 hens (no rooster) and here are some of the problems I've been running into. Three of my girls have their neck feathers (down the front) plucked bare, 3 others have parts of their wings plucked down to their feather shafts and one girl has no tail feathers but not a bare bottom/vent. Their coop has been treated repeatedly with diatomaceous earth as have all the girls because I assumed they had mites and blue cote for the exposed necks and wings. We had leg mites last year and although their legs took fine, I can't figure out why there are all these issues. Another one of my girls also had to be separated because her comb and waddle had been almost completely pecked off, she is recovering after antibiotic treatment and solitude. Any input would be greatly appreciated.