Frontline Plus Provides Your Dog With The Most Complete Spot-on Flea And Tick Protection Available. In Addition To Killing 98-100% Of Adult Fleas On Your Dog Within 24 Hours - FRONTLINE PLUS Contains A Special Ingredient That Kills Flea Eggs And Larvae - Too - And Keeps All Stages Of Fleas From Developing. By Effectively Stopping The Development Of New Fleas. Completely Breaks The Flea Life Cycle. And - Kills All Stages Of 4 Major Ticks Including Those That May Transmit Lyme Disease And Rocky Mountain Spotted Fever. It's Completely Waterproof. Kills chewing lice. For Use in Puppies 8 Weeks And Older.