Zodiac Spot On Plus Flea & Tick Control for Cats is a long lasting product specifically formulated only for cats and kittens to prevent and control flea infestations. This spot on kills fleas before they hatch which prevents flea eggs from maturing into biting adults. It also kills biting adult fleas, deer ticks, and mosquitoes your cat may acquire from its surroundings. A single application will provide egg hatch inhibition for up to 30 days.