I use Spectracide Triazicide granules. They last all season and are also good for ticks. Follow directions on the package. Get your dog dipped also.
Hi Shopper, first cut the grass as low as possible. Remove all debris and stop watering. Fleas like the shade and they love moist areas. You do not need to treat sunny areas. Fleas will not live there. Use cedar chips where your animals lay outside. Sprinkle food grade diatomaceous earth in all your shaded areas. Reapply after rains or high humidity. Diatomaceous earth is fairly inexpensive and comes in large bags. Wash your pets with blue Dawn soap. Spray apple vinegar on them -- avoiding the eyes -- after they are dry and gently rub in. Be vigilant. Fleas multiple quickly and can easily overrun a house.
You need to apply a pesticide.
Buy a flea fogger. Each can covers 2,000 square feet and lasts for several weeks.