Fleas are a type of biting insect pest common throughout the U.S. Fleas not only bite humans and pets, causing physical discomfort and itchiness, but may also carry deadly diseases. Eradicating fleas in your house and on your pets requires a comprehensive treatment plan, and may include killing outdoor fleas in your yard to prevent the parasites from invading your home.
Mow your lawn with a standard riding or push lawn mower, and trim any overgrown shrubs or ornamental grasses. Fleas enjoy shaded areas. Increasing the sunshine in your lawn may deter the pests.
Water your lawn thoroughly once a day using a sprinkler or water hose. Cover all areas of the lawn, including edges near walkways and fences. Excessive moisture, such as that created during regular watering, will drown the moisture-susceptible flea larvae and adult fleas and drastically reduce the current flea population.
Treat the lawn with a flea insecticide if flooding alone doesn't control the fleas. Pyriproxyfen-based insecticides are widely used and intended for outdoor use because they are stable in sunlight and have a residual effect that lasts 6 to 7 months. Pyrethroids or methoprene-based insecticides may be used if your lawn is shaded. Apply according to the manufacturer's instructions, as flea insecticide potency varies widely by product.
Apply a biological treatment of the Steinernema carpocapsae nematode---a microscopic animal that feeds on juvenile fleas---to kill the flea population as an alternative to spraying potentially toxic insecticides. Nematode sprays can be obtained from most nurseries and some garden stores. Spray as you would a normal insecticide, following the guidelines of the nematode formula manufacturer.