Harris Boric Acid Roach Killer Powder with Lure Creates a barrier through which cockroaches and other insects must crawl. Puff a light dusting of powder in areas such as behind refrigerators, along baseboards and in cracks and crevices where roaches have been seen. The powder contains a lure that roaches will seek out. Take measures to ensure that the powder is kept dry in order to remain effective.
Boric Acid works by interfering with the roach's digestive system. In addition, the powder will cling to the outside of the roach, helping to kill other roaches when the affected roach returns to the colony. The powder is fast acting; insects coming into contact with the boric acid will die within 72 hours.