Pet Hartz UltraGuard One Spot for Cats, cats, flea, drops, collar, hartz, one, spot, treatment Supply Store/Shop An easy to use topical application that Kills flea Eggs and Larvae for 30 days It also provides relief from flea populations on cats and kittens by controlling and preventing flea dult fleas can live on your pet while also producing vast numbers of eggs which drop off your pet Kills flea eggs and larvae thereby breaking the flea life cycle