So I need some help with the final touch to my duck run. What should I put on the ground ?? I live in the city ,so it has to keep smell ,mess ,and flys down as much as possible. I've been think a bottom layer (2" or so thick) of large river rock or something ,to allow for good drainage. Then a 2" layer of pea gravel. I was also thinking of perhaps planting a few low plants/bushes in the run. My plan is to add Stall Dry or Sweet PDZ as a bottom layer inthe duck house ,with shavings on top. In the run ,I will sprinkle it on top of the gravel in the run ?? Is there anything I can do to make them smell ,mess and flys down to an absolute minimum ?? They ducks are two muscovies ,if it helps Edit : I was also thinking of planting Tansy ,Thyme ,Basil and Chamomile ,along with perhaps marygolds around the run ,to keep away flies.