How long does it take for frontline to work

It takes about 24 hours to kill the fleas. In the meantime, vacuum your house really well and when you're done, throw the bag in a plastic bag and put it outside into the trash can. If you have one of those vacuums that have a wind tunnel thing, empty it into a plastic bag, outside, and leave it out there in the trash can until trash day. Fleas can live about 30 days without eating. You may need to spray your yard to kill any fleas out there, and also spray your house. If you have a bird, be very careful and maybe let the bird stay with a friend for a few days. Good luck. This is a very bad year for fleas.