https://entomologytoday.org/2016/07/18/battling-chicken-mites-with-bags-of-brimstone/
"...Sulfur dust has been used for decades to control mites on chickens. The sulfur is usually provided to chickens in a “dust bath,” essentially a box of dust, which may contain fine dirt, sand, diatomaceous earth, insecticides and other powdery substances. The chicken sits in the dust and fluffs it into its feathers to remove parasites — this is a natural chicken behavior. Sulfur dust baths are very effective at controlling northern fowl mites, even for chickens in the same coop that do not use the dust bath. But dust baths may not be practical in larger commercial poultry houses where numerous chickens dust bathing might cause a large amount of sulfur to be kicked up into the air...."