This aqueous equine insecticide spray features a ready-to-use, citronella scented formula. It won't attract dust and grime like oil-based products and offers long-lasting protection against a wide array of insects. Nulli-Fly can be wiped or sprayed on horses. This value priced product is sure to be your next favorite. WATER based formula. Quick knockdown. Kills and repels: deer ticks that may carry Lyme Disease, Stable Flies, House Flies, Bot Flies, Horse Flies , Horn Flies, Ticks, Deer Flies, Mosquitoes, Fleas, Face Flies, Gnats, and Lice.