Hi Maddie, we, too, use Frontline and it does kill the fleas and
eggs; however, the problem with an outdoor
cat is there are fleas out there, so new ones jump on. Jade is outdoors in the summer ALL the time so we are faced with the same problem. I don't actually see any fleas, but she starts scratching well before her next application is due.
Something else. We've been using Frontline for 5yrs, but due to finances, I went with Advantage this month and it seems to be working great.