I've had my girls for almost a year now and about midwinter I noticed that a few were missing feathers around their necks. (In the front, not like from rooster attention). It wasn't severe and I didn't think much of it. It didn't get better or worse. Fast forward to now and a my girls are pulling out each others feathers and eating them. They don't seem to do it out if aggression or bullying. Also my eggshells started to get pretty thin. And my Welsummer hasn't laid an egg in almost 2 weeks. I figured I had given them too much scratch and they were deficient in protein. So I bumped put them on feather fixer and only give sunflower seeds as treats. They always have Oyster shell available to them but I've been giving them extra just scattered in their run just in case. I also put a bunch of DE in their dust bathing area in case there were mites or anything. A week later no improvement. I put them on "Strike" wormer for 3 days. Nothing so far. Still no egg from Jenny (the Welsummer). Now she keeps trying to lay down (she doesn't seem lethargic for the most part except when she randomly lays down. She is still scratching around and eating and preening) except when she lays down the others all try to pull out her feathers. I have no idea what could be wrong with them or her.