Using Advantage on animals is supposed to care of house and yard infestations, not just just the fleas on the animals. At least that's the way it was marketed at the vet clinic where I used to work. The new generation of flea control is much better then the old washing with flea shampoo and spraying or sprinkling with permethrin or other insecticides. I've half considered getting the spray on Frontline for my lower legs in tick country. It's counter to the label to use on humans, but since it's not considered harmful to dogs or harmful to people petting those dogs I don't see the problem using it on my clothes.