Neem Oil is an essential oil which is thought to repel most insects including fruit flies, wasps & horse flies. It is very strong distictive smelling not pleasent to the human nose and very bitter in taste. We have also added Lavender and Peppermint to make the smell more pleasent. Also repels fleas, ticks, mites and lice along with most biting flies doesnt seem as effective on common flies as Citro EXTRA tablet or DEET EXTRA Tablet. Wont stain white marking like gel versions.