I keep bringing containers full of mulch and throwing in the run. The people who trim trees and grind them up dump all that, at our University Orchard in North Las Vegas, and its free to anyone. Once a month I throw the containers in and they are so busy moving it, pecking it, and just having fun, that I really look forward to doing this. I started this when I discovered the natural ground being so full of stones that they were hurting the feet of the hens, and so-- mulch seems to be solving that problem. But the ground up wood I think will be warmer on their feet this winter than just the earth.