boredom or pecking order I guess. Don't seem to necessarily due to nutrition but I'm sure that could be another reason. Seems like our fawns do it much more than the adults. If its cold and they are pulling too much out you may have to keep her inside til it starts warming up.
I have had a few grown does with the same thing in the last month. Vet says it could be lice but we havent seen any lice. She said the vetremic wormer or cydectin wormer willl cure it. We just started our vaccinations for our whole herd this week.