J.T. Eaton's ANSWER® Boric Acid Insecticide Dust controls cockroaches, palmetto bugs, ants, silverfish and fleas. It can be used in several different applications, including crack-and-crevice treatment for walls and baseboards, placed into cabinets and drawers or blown into wall voids. The product can even be used in rinse water: After washing floors, add one cup to one gallon of rinse to leave a thin application of powder. The residual packs a lethal dose for foraging roaches.