Pre-Strike Mosquito Torpedoes kill developing mosquitoes in standing water before they become breeding, biting adults. When dropped into standing water, the Mosquito Torpedo sinks to the bottom and leaves water crystal clear. Once there, it slowly and continuously releases Insect Growth Regulator (S)-Methoprene into the water to prevent mosquitoes from developing. Mosquito larvae exposed to the treated water will die in the pupal stage before they reach adulthood. Can be used in animal watering troughs, flooded areas, swimming pools, and other areas of standing water. Each Mosquito Torpedo provides up to 60 days protection.