Frontline Plus for Cats provides your cat with the most complete spot-on flea and tick protection available. In addition to killing 98-100% of adult fleas on your cat within 24 hours, Frontline Plus contains a special ingredient that kills flea eggs and larvae and keeps all stages of fleas from developing. It effectively stops the development of new fleas, and completely breaks the flea life cycle. It kills all stages of 4 major ticks including those that may transmit Lyme Disease and Rocky Mountain Spotted Fever. It's completely waterproof and is gentle enough for use on kittens.