The article The Cold Coop in the last BYC newsletter refers to use of a hover over the perch in winter to help the chickens stay warm. Has anyone used this to help with winterizing the coop? I have an 8x10 shed coop and 12 chickens. We have one long roost. I'd like to figure out how to build something like that over half the roost. I'd like to see hear what others have done.