Ant Killers: Combat® Source Kill Max Ant Killing Gel helps you get rid of ants in just three to five days. It's formulated to attract ants quickly, while its fast-acting insecticide, Fipronil, one of the most powerful ant killers, starts to exterminate ants in hours. Worker ants return to the colony and feed the bait to the larvae and to the queen, eliminating the entire ant colony. This gel is easy to use so you can apply it in cracks, crevices and other hard-to-reach places.