This afternoon when I checked on my 2-week old chicks (brown-egg laying assortment from the Hatchery) I noticed one of the chicks peeping like it was in distress. It was frantically pulling at it's own tail feathers and peeping. I picked her up and looked and it didn't look like anything was wrong with her vent, just most of the fuzz and feathers were missing. I put some bag balm on there since that's all I had. The other chicks don't seem to be bothering her and none of them have been picking. They are under a red light in a good-size brooder in our basement, plenty of clean food & water and seem to be comfortable. I did isolate her but not sure if it will get better since she's doing it to herself!!! What else can I do and what may be causing her to do this?