Hi there, thanks very much for your replies. We are officially in Spring time here, the weather is actually ideal at this time of year; not too hot and not too cold. She started out with whispy fluff at the base of her tail (which I have noted with another hen and a rooster) and I didn't take too much notice and then suddenly no back feathers and when I lifted her off the roost to check more thoroughly she is missing a LOT of body and back feathers, so I was concerned and wondering if it is an infestation or food issue. I do not feed pellets or mash. I feed good wholesome food, and they free range every day with fresh water. Tonight they will get rice, greens and fish. They have free choice corn and wheat, oyster grit and I am wondering if there is anything else I should be doing? Just sprayed their roost again.