Hexamite used for ear mites is a pesticide designed to kill the mites. Ear mites are a form of blood-sucking parasite that live their entire lives within the ear canals of your pet. They thrive in the dark, moist environment that the ear provides. Mites cause severe itching and irritation for the pet and can cause ear infections if left untreated. In addition, the pet may cause injury to itself by repeated scratching in and around the ear.