Not only does FRONTINE Plus kill 98–100% of adult fleas on your pet within 24 hours, it also contains a special ingredient that kills flea eggs and larvae to keep all stages of fleas from developing and bothering your pet and your familyFRONTLINE Plus remains waterproof for 30 days, even if your dog or cat swims or is bathed, and is gentle enough for use on puppies and kittens 8 weeks of age or older. FRONTLINE Plus is the most complete flea and tick control available. FRONTLINE Plus completely breaks the flea life cycle by effectively stopping the development of new fleas. FRONTLINE Plus kills all stages of 4 major ticks including the one which may carry Lyme disease.