I have several hens that have had there feathers plucked off their backs by other hens. Some are worse than others and the odd one is hardly touched. I have been told it is a nutritional issue and they are missing something. Some say it is a pecking order. Has anyone experienced this before and what have you done to remedy the problem. It looks painful and uncomfortable and in the summer may not be as bad but with winter coming I am sure they will feel the cold.