One of my barred rock hens has a bare spot with no feathers on her butt about an inch or two under the vent. Around the bare spot the feathers are sparse and look kind of stringy. It rained yesterday and today I noticed it. (I'm not sure if the rain had anything to do with it.) She is at the top of the pecking order so I don't think it's feather picking. The bald area isn't red or swollen or anything, it's just doesn't have any feathers. I don't have a rooster either. Does anyone know what this is???