Something I am trying that I thought may be of interest to some in regards to dusting your chickens for mites. I had a plastic round pond pan, about 3 ft in circumference and about 6-8 inches deep. I dug a hole in the ground and put in down into it so that the top of it was closer to ground level. I have a wire dirt screening apparatus that I laid on top of it and proceeded to put dirt from my garden on it to screen it into a finer course of dirt to fill the pan. Since it is now really light weight dirt without any rocks or clods, it is very easy for the chickens to dig in it and do their dust baths. I had read about using powered Sevin dust for mites. I mixed some into the soil and now when the chickens do their dust bathing they can take advantage of getting a little bit of the Sevin dust up into their feathers, under their wings, etc. I hope that it was a good thing to do. If anyone thinks otherwise please feel free to let me know.