As the most advanced formula Absorbine offers, UltraShield EX fly spray delivers proven fly control horse owners like you depend on for the comfort and protection of your horses. When you need to eliminate fly frustrations, reach for The Fly Spray in the Black Bottle. UltraShield EX can also function as a premise spray—an important part of your overall fly control strategy. Premise sprays are commonly used to kill biting and nuisance flies, as well as crawling species such as deer ticks and carpenter ants on surfaces inside your barn.