I am new to chickens, and I have 9 Rhode Island Reds. One of my girls was badly pecked after we got her, but we put Blu-Kote on her, and I even put Rooster Booster on her to keep the others from bothering her. She is no longer getting pecked, but she is not growing her feathers back. I noticed that she was acting strangely tonight in our bark mulch. She was rolling around and almost looked half dead at times. When I approached her she got up and ran off. She is eating, but the feathers on the back of her neck are sparse too. All of the feathers underneath are gray. Why? I have mostly young chickens, and she is not laying yet to my knowledge. I checked her all over tonight, and I couldn't find any lice, mites, etc. She is acting normally for the most part, and she is socializing with the other chickens. Any ideas what could be wrong with her? Thanks!