A few days ago I found flea dirt on Poppy, and a rigorous combing turned up one flea on her, several on Sophy, and (surprisingly) nothing at all on the cats. I don't treat them routinely as we rarely have a problem, but fortunately still had supplies of Frontline Plus for dogs and Advantage for cats in the cupboard (it was, of course, a holiday weekend...). But the last outbreak we had proved to be Frontline resistant, and had built up to a significant infestation by the time I finally found something that worked. I have been combing all the animals several times a day, drowning the occasional flea as I found them (very satisfying, by the way), but today the only one I found on Sophy was very small and dead. Hurrah! The drops are working! If I keep up the vacuuming, washing, combing etc I may be able to avoid really nasty sprays and flea bombs, which I hate having to use.