Combat Roach Killing Bait Strips, 10 Count (Pack of 2) One of the fastest roach-killing ingredients available. Insect nerve poison kills roaches by contact or ingestion. New discreet design starts killing roaches in hours, so you can see immediate results. High secondary nest kill. Kills roaches in a domino effect, eliminating the source of the infestation. Easy-to-apply to hard-to-reach areas.