The duster sold here will direct the TNT powder exactly where you want it, making this the most cost effective way to dust hay supplies. A thin coat of TNT on the hay will limit the number of ticks, fleas, lice, mites or other crawling bugs from setting up nests in your barn or storage areas. We recommend you wear goggles and a dust mask when dusting because TNT can cause temporary irritation to your eyes, nose or lungs. It will flush away and any irritation will diminish. There are no lasting effects and once the powder dust settles, the area it completely safe for barn cats and other mammals to inhabit.