I know all about fly control in the coop/run and hardly ever see any there. We use a mixture of sand/DE/Sweet PDZ which works really well. My problem is I let my hens out at least once a day, sometimes twice to free range in my yard and they poop everywhere. Because we water 2-3 times a weeks and the poop gets wet, this attracts the flies. When the hens are locked up I'll leave a yellow sticky trap low to the ground and that helps, a little but not much. Any suggestion on fly control in my yard that's safe for the grass and hens?