Combat Roach Killing Bait Strips are great for control of indoor and outdoor cockroach problems in household situations. They have a discreet design, kill the nest and are easy to apply. How Combat Roach Killing Bait Strips work: 1. The bait attracts cockroaches in search of food and water. 2. Cockroaches eat the bait. 3. Cockroaches take bait back to nest, where it is transferred to other cockroaches. 4. Other cockroaches are exposed to the insecticide and the entire nest is killed