Combat Max® Roach Killing Bait for small roaches is designed to kill German roaches and other small roaches. Formulated with food that roaches prefer and the powerful fipronil insecticide, which starts killing overnight. The roach killer bait works 24/7, killing the roaches you see and the ones you don't, and provides quick results. These roach killer bait stations target the nest to eliminate the source of the problem. Simply place the Combat Max Roach Killing Bait Stations down, for up to 12 months of continuous protection day and night. Use these baits under sinks, behind toilets, and behind appliances. No vapor, fumes, mess, or odor roach bait station. Replace all baits every twelve months, or sooner if roaches return.