Although this won't deal with them outside it will make sure your inside doesn't get infested( unless already too late ).
Go to your local ACE Hardware( or similar )and get a 1/2 dozen or so flea traps. It is a device that plugs into your wall socket and has a changeable piece of sticky paper( like fly paper )and an LED light. At night the LED shines on the paper and it attracts fleas in the room. They jump on the paper because of the light and get stuck.
Place a couple around the house and watch the paper to see if it catches any. Change the paper every week or so until no new ones appear.
If they get in your home and lay eggs you are in for a nightmare. You will have to strip every bed and wash all bedding, wash all curtains, etc... You will have to vacuum every square inch of the house very thoroughly with a good strong vacuum, and you will have to treat the place with some type of flea bomb.
My house got infested with fleas( as did poor Sadie )2 summers ago and it took MONTHS to get rid of them. Everytime I thought I had it a short time later a new batch of eggs hatched and I had to start over.
Best of luck. This is no joke and is a serious pain if they get inside and setup shop so to speak.