My horse was being attacked by a swarm flies when I decided to spray him to give him some relief. The flies disappeared within seconds!!!! I sprayed in all the areas wher the flies like to hang out....like belly, legs, mane, tail, chest and neck. After about 4 hours; still no flies!!! This product is a keeper in my arsenal of the spring/summer fly war. This spray works!!! I could not believe the awesome positive results I got with this product. Finally something that does exactly what it claims to do....I pray the manufacturer won't change anything about this product.