I found a couple fleas on my cat. I was surprised as usually fleas on a pet meant fleas occasionally jumped on me, but I've never had a flea jump on me all Summer/Fall. The cat has been scratching more than usual lately so I put a correct dose of the Frontline Flea killer stuff on it 2 days ago. It is supposed to kill 100% of fleas within 12 hours, but 2 days later I see one? I suspect there are more. So what is the deal? I know they can jump back on from the carpet (and should die shortly thereafter) but I don't think we have many in the carpet because they never ever jump on me. I spend a lot of time sitting/laying on the floor and just do not see them on me. So does this stuff take longer than they advertise to work?