Mycodex All-In-One Flea & Tick Spray controls fleas, ticks, lice, mosquitoes, gnats, flies, and flea larvae. This product combines the adult flea killing power of pyrethrins with the long-lasting egg-killing power of PRECOR Insect Growth Regulator. This highly effective combination of ingredients provides quick relief from biting fleas and continuous killing of flea eggs laid on the animal, breaking the flea life cycle. The elimination of both adult fleas and flea eggs is important because adult fleas live on your pet, causing discomfort and skin irritation, while the vast number of eggs that they lay fall off and develop in your house. Effective flea control requires treatment of your pets, house, and yard.