Nulli-Fly Water Based Insecticide Fly Spray for Horses is a ready-to-use, water-based, citronella-scented formula. It won't attract dust and grime like oil-based products. Quick knockdown and long-lasting protection against a wide array of insects, including stable flies, house flies, bot flies, horse flies, horn flies, face flies, ticks, deer flies, mosquitoes, fleas, gnats, and lice. Pyranha Nulli-Fly contains 0.075% pyrethrins and 0.15% permethrin.