3 of my 5 chickens have these bald spots above their tails. I have not witnessed them pulling these feathers, and I have also not noticed a large number of feathers in their coop? So today was the first day I've let them outside to forage in a while (I leave for work in the dark, and come home in the dark, so I can't take a good look at them sometimes!) and that's when I noticed this. I have 1 EE Rooster, 1 Buff Orpington hen, 1 Barred Rock hen, and 2 Americauna hens. The bald spots are on the rooster, the buff orpington, and one of the americaunas. Please help -- I'm new to chickens, so I need all the help I can get. I live in MT, and the weather is below freezing everyday. They live in the barn, under a heat lamp, but it's still cold in there! They are all 7 months old, and they are still laying eggs daily (I thought that would stop with cold weather, but it has not!) Their feed is Purina layena, and about 5 days a week, they get a cup of cracked corn. Is there anything I'm missing in their feed that might prevent this feather loss? Do I need to worm them? What am I missing? And more importantly, where can I pick up the items you're suggesting! Thanks!