OK, I have tried everything... half of my flock have no feathers on their backs. Thinking they might have lice, I've dusted & sprayed the coop with melathione. Yes, the rooster is fairly vigorous...but not really that bad. I've got 18 hens to one rooster, so it's not overkill. Is there something I'm missing?? It's kindof embarrasing. It's not like they're mouling, unless they've Permanently moulted? I have never seen the like. Feedback would be great.