The Daily Dose Equine Bye Fly Supplement for Horses is an easy, non-spray feed supplement for horses subjected to assault by flies, ticks, mosquitoes, gnats, no-see-ums and other insect pests. After ingestion, this supplement kills adult and larval forms of insects, including horseflies, house flies, gnats, mosquitoes and ticks. The powdered mix can kill bugs that attempt to crawl or alight on the horse, as well as those that are internal, such as worms. Use this horse supplement with adult-aged horses. The powder form of this supplement is easy to feed and digest.