Advantage Stops Fleas From Biting In 3-5 Minutes, Kills 98-100 Percent Of Fleas Within 12 Hours Of Application, Kills Re-infesting Fleas Within Two Hours And Lasts Up To A Month. Kills Fleas Before They Lay Eggs. One Treatment Prevents Further Infestation For At Least Four Weeks. 6 Topical Monthly Treatments.