Hello, I'm pretty much a novice in chicken keeping and am struggling with keeping the coop clean. I have 5 chickens in a 7'x13' pen (and a hen house) which I placed on my back patio. I wanted them on concrete to discourage predators digging into the pen. At first I left the concrete bare, but the poop stuck to the floor, making it difficult to clean. Since I don't have a roof over the pen, I didn't think straw would work, as it'd get soaked every time it rained so tried sand instead, likening it to a giant litter box from which I could just rake out the poop. This isn't working well either as when it rains the poop just disintegrates making it impossible to remove, and the odor and flies are increasing which is not good as they're located right outside my patio door! I am now considering moving them out onto a section of lawn. Would this provide for the easiest upkeep? Can I use hay, even if there's no roof over the pen? I'm thinking that when the grass is gone, I'll again have to put something down. Also, since I let them have the run of the backyard a few times a day, poop is accumulating all over. I'm considering a shop vac. Any suggestions are greatly appreciated!