Ours like to dust bath in the dirt we get from the dump. It is supposed to be compost, but it is too dry and doesn't hold water. I am hoping after this year I don't have to buy it anymore, too worried about what might be sprayed on the material that are in it. Before that, they just found a couple of nice spots where there was no grass and had their fun. My littles just made a spot in the grass and got their dust bath on.I use garden soil (organic) with wood ash. Some add peat moss, and I will most likely, but haven't bothered with that yet.