I just got chicks and a 4'x8' coop and run. The coop is about 2'x4' and sits on top, while there is a 4'x8' space under for the chickens to run around. Part of the run that's not under the coop has no roof. The whole thing sits on top of dirt. Do I need to clean the poop off the dirt floor? Should I put pine shaving on the dirt floor? Here in SF Bay area, it doesn't get that cold, but what happens in rainy season? Will the chickens just run around on the wet muddy dirt? How do I clean the poop in wet rainy season? Thanks.