Advantage Spot On Flea Control For Cats 9 Lbs. and larger. Advantage may be the quickest acting spot on flea control. It does not kill ticks. Each application lasts about a month. Advantage is sold as a single application. Do not use flea spray, shampoo, or collars with Advantage. Do not allow children to hug or pet your cat at the application site for about a day. Do treat your home with premise spray if you have had fleas.