Stop annoying fleas and lice in all life stages with Advantage II Flea treatment for cats and kittens. Advantage II Flea Treatment for Cats and Kittens prevents, treats and kills all stages of fleas and lice. Superior flea control kills through contact, so fleas don't need to bite to die. The main active ingredient, imidacloprid, kills all present fleas within 12 hours of initial application. Advantage II also includes pyriproxyfen, an insect growth regulator which prevents flea larvae from reaching adulthood.