I have a 3 month old white crested black polish. She has a bald spot about the size of a nickel on the back of her head. I was not able to spot any kind of bugs, nor is there any open skin or bleeding. It is bare skin and what looks like some little broken of spines of where the feathers were. Any info would be great. Does this sound like some sort of illness? Or is she maybe getting picked at? All of our birds are same age. We have 15 total, 2 roosters. Tried to get a photo but it's not a great one.