4-Undecanone is a natural ketone primarily used as an insect repellent, effective against mosquitoes, ticks, fleas, and other biting insects. It is incorporated into lotions, sprays, and topical formulations for human protection from insect-borne diseases, as well as in pet care products for animals like dogs and cats. In agriculture, it protects crops from pest infestations, serving as an eco-friendly alternative to synthetic pesticides due to its natural origin and low toxicity. Additionally, it is used in the food industry as a flavor and fragrance additive, imparting a unique fruity aroma. It is also employed in research to study insect behavior and develop new repellent technologies.