Boric Acid formula with added lure, kills Roaches, Waterbugs & Silverfish. Just place tablets in out-of-the-way areas where roaches travel and roaches will find them. One box can treat an entire house, making it one of the most efficient and cost-effective ways to kill a roach. Place no more than twelve tablets per room in sites, such as under and behind refrigerator, stove, sinks, tubs, dishwasher, washing machine, dryer, into openings around drains, water pipes and electrical conduits, and in cracks and crevices along baseboards and corners of cabinets, cupboards and closets. Remove all lower drawers in kitchen and bathroom cabinets, bedroom dressers and chests of drawers. Then place tablets in drawer wells. Any tablet visible after application must be pressed into cracks and crevices or removed. Reapply as necessary. This item is registered with the EPA (No. 3-1).