Kills roaches & eggs at their source. Advanced formula (vs. the previous Combat bait formula). Kills roaches and eggs for 3 months. This product provides complete roach control. Prevents roach reproduction. How Combat Source Kill 1 Works: 1. Roaches enter the bait station and eat the bait. 2. Roaches take the bait back to the nest. 3. Roaches share the bait, killing other roaches and destroying the nest. Bonus Pack: 50% more free. Made in USA.