 then the fleas, once they grow up and become adults, will have no one else to bite, perhaps but you. Unless you have a dog in the house that's not protected. Oh, no dog, just a cat. Okay, because, so you'll know soon enough if there are other fleas, or if there are fleas that are kind of growing up in your house, which I suspect might be the case if you have that many on your cat, because they won't be wanting your cat, and they'll be really hungry, starving,