I have an 18 month old RIR and BA. Both had been favorites of my rooster which I've rehomed back in the beginning of the Spring. Both have bald spots on their saddles and heads. I've tried applying pine tar and blue cote to the bald spots, but the bald spots remain. I'll see new feathers just coming in and then the next day they're gone. I don't see the others hens pulling them out. If anything they are pulling them out themselves while preening. The feathers look more like they are broken off at the base. It's started to get worse now with the heat and humidity and they look kinda itchy. The skin sometimes looks red and other times not at all. I've looked them over repeatedly and see absolutely no signs of mites or eggs or any live creature of any type on them. Just little broken feathers. Could this be a skin condition that has developed because they had the existing bald spots? Any advice would be great!