If Frontline was a person, it’d be a hard-nosed veteran, tough and leathery as old boots, who’s been around the traps and won’t take stick from nobody. Frontline has been fighting the war against fleas for years and knows their every move. Frontline Plus Cat Green has a bit of extra ammo to knock out fleas at every stage of their life cycle: egg, larva, pupa and adult. One application will keep your cat protected for at least a month. Product details Safe for use on all cats, kittens over eight weeks old, and pregnant/lactating queens kills fleas at all stages in the life cycle provides protection for one month unaffected by water treats and controls flea allergy dermatitis kills fleas in the pet’s surroundings.