I've had chickens for about 4 years now at my home in San Diego. The chickens are in a run we built on the side of our house. It is enclosed with chain-link fence and the coop is inside the run. The run is made up of three terraces because our house is on a slope. When we first built the run we didn't have a substrate in the run, but the chickens made a ton of dust from constantly scratching at the dirt ground. We then added small, smooth pebbles. That has worked decently well and really eliminated the dust, but the problem is that over the course of the last several years most of the pebbles have migrated down to the lower terrace with all of their scratching. So I now have a chain link fence that is bulging with pebbles it's barely holding back! I'd like to get rid of the pebbles and replace with something else, but can't figure out what would be best. Sand would just get kicked out of the fence. Has anyone used mulch or bark chips? Anything I haven't thought of?