Maxforce FC Roach Gel Bait 60gram tube has the active ingredient, Fipronil, which provides a unique mode of action that works through both ingestion and contact, knocking down roaches and ants that eat or simply touch the bait. This offers a Domino Effect delayed killing action enables one contaminated roach to kill many others where they live and breed. A foraging roach is guaranteed to receive a lethal dose from a single feeding, but lives long enough to return to the harborage where its poisoned feces are consumed by other roaches. Fipronil has no known resistance in roaches and is odor-free to customers.