OK, i need some advise on how to fix my chicken and duck runs. Because i have had chickens for a while the ground is uneven and every time it rains there are always huge water holes in the run, especially in the ducks run and it gets smelly to. I have never used any material for my chicken or duck runs, so i am new to this. Would Pea Gravel work to fix that problem? Is it safe to use around ducks and chickens? and is there a specific kind of pea gravel for chickens and ducks?