All of my hens are bare-backed, though a few are less bare than others. At first I thought it was my Barred Rocks (they kept their feathers longest) attacking the other hens. A friend suggested lice or mites, but the rooster and the guinea hen have all their feathers still. I was reading here today, and noticed it could be the rooster doing it (which also explains why he and the guinea hen are fine) ... or the hens could be eating the feathers for protein. We also have egg-eating going on. Sigh. Which could also be a lack of protein. We moved them into a barn (no run) for the winter, because we didn't agree on a better location to build a coop and run before then. They'd been in a pen w/o adequate shelter for winter last Summer and early Fall. We are building a hoop style tractor at the moment (almost done) and we moved some of the hens into the old pen last night, to help give them more space if they were crowded. Some are still in the barn. Any thoughts on how to know if it's lack of protein, or not? What is the DE that was suggested for treating mites? Does it work for lice, too?