Bob Martin Flea & Tick Spot On for Cats Bob Martin Flea & Tick Spot On for Cats is clinically proven to repel fleas & ticks on cats & kittens from 12 weeks of age. Each application of Bob Martin Flea & Tick Spot On will provide up to 4 weeks protection. This 4 week pack contains 1 application to treat 1 cat for up to 4 weeks. Bob Martin Flea & Tick Spot On is only suitable for cats & kittens over 12 weeks of age. For kittens under 12 weeks, carefully use a flea comb to remove fleas.