When I started researching chickens last spring, the two things that kept coming up in my reading were the importance of keeping things clean and of keeping things dry. Chickens + wet seems to lead to trouble. I guess I got that point across to DH pretty strongly because he arranged to have the pen covered with this corrugated plastic: It's clear, so the light comes through, but when it rains, we now have a great big umbrella over the pen. Yesterday the neighbor kids came over to visit the chickens and sat in the pen with the chickens, drinking hot chocolate and doing their homework while it poured rain. Everyone stayed perfectly dry!