A few weeks ago I noticed one of my hens eating a feather that was laying on the ground. I thought she jus happened to see it and picked at it then jus ate it for no reason. Then 2 days ago I was in the coop with them when the rooster bred one of my black orps. and he pulled out like 6 or 7 feathers from her neck. Before the feathers could settle on the ground the other hens ran over and gobbled them up. My girls are not hungry. not for food anyway. they always have plenty of food and water and get treats like carrots lettuce and cabbage every day or 2. what could be making them act this way? am I leaving something out of their diet that they need? they eat dumar 16 % layer crumbles plus the treats I already named. any advice will help.