wow! i feel much better! i just turned our lean-to into a coop and it's made of close-knit lattice on 3 walls. i was so worried about that! well, i did some research on "open air chicken coops" and i'm not worried anymore! there's loads of websites on it, so if anyone does a search, you can read about it. one website said that chickens would be better off roosting in the trees than a poorly ventilated coop. very interesting articles.