I have the poodles out in their 10x10 run when we are doing other things and can't keep a good eye on them. They've dug up the grass in the three places we've put it. The dust is unbearable, they look like Pigpen running around creating dust clouds! what can we do to stop all the dust? Would a layer of woodchips work, or would they just dig those, too? Any ideas at all?