First off, never in my life have I seen so many flies around a chicken run. The birds have been in it for 2 days. I think it's because no one but me picks up after their dogs in this whole neighborhood, the flies caught a whiff of chicken poo, and came flying over. There isn't a farm for MILES, this is suburbia. Sand dries out the poo, decreases odor, and thus flies then too, right? But how do you clean it? Like a giant litter box? And how about fly control? This is insane.