We have 4 different hens, all just over a year old. In the last two months, one of them has started to get picked on. The others are eating her feathers off her head/neck/chest and back side (from what I can tell). There has been no major disruption to their home or diet or anything like that. I read it could be low protein so I have given them various protein treats along the way like tuna fish, yogurt, etc. I have used the medicated ointment Rooster Booster which doesn't seem to do a thing except make our poor Red Bird look silly. I think I know who the leader of the pack is, but they all seem to get along really well. I have witnesses 2 of the other 3 nipping a neck feather so I don't think it is just one bully. All other three have the most full amazing feathers and then there is this scrappy looking lady. She has some tiny new feathers growing in on her neck/head but I think the others must break them off as soon as they are long enough to do so. I don't know what else to do, any help?