I am having a problem with a couple of my does eating the hair from others. At least that is what I think is happening; I have not yet seen this first hand but have seen a hair or two in some mouths. I currently have two does that have absolutely no hair in large areas on their sides (5"x10"). In the cold Northern PA winters this is worrying me. One deer's skin has turned dark brown. Should I be concerned? If so, what should I do? Any help or advise is appreciated.