We have 16 hens, and they have had quite a lot of feather "problems" for the last 2 months. I do not have any roosters, there is one mean hen, but her pecking is minimal, and we have 3 geese in with the hens, but again I have seen very little bullying/pecking. They are not lethargic in the least, they rush me every time I go out to see them (they go crazy when they get vegie/fruit scraps lol ) They have a very large pen, and free range most evenings/afternoons. We collect 8-14 eggs a day, and change the nesting often. They are on a layer pellets, and have access to calcium. We ordered them from Murray McMurray 11 months ago. I have never experienced this kind of feather damage, and do not now how to cure it. I have powdered them with a mite pesticide, and sprayed an oregano/vegetable oil mix on the roost and in the corners of the hen house. I have not noticed any change. I have not seen any mites or bugs other than a few spiders (I have looked at the hens and around the coop). I have had many requests for chicks this spring but I do not want to bring a rooster in until they are back to normal... What kind of pest/illness is causing this. How can I cure them? The photos are of the worst spots on a few of the hens. My poor hens are awful raggedy right now.... Please help. Thanks.