Fleas don’t live in grass. Lawns don’t provide enough protection from environmental conditions. Fleas require a habitat that’s shady, humid, and wind-protected. Additionally, some sprinklers keep the ground too wet for fleas to survive. Larvae die when soil moisture exceeds 20%. The water also dissolves adult flea feces, which larvae rely on for food.
Lawns aren’t Viable Flea Habitats
Places where fleas can develop outdoors are limited. To survive, they must be sheltered from extreme environmental conditions. Developing stages rapidly die from desiccation in open, sun-exposed areas. Viable habitats are shady, humid, and shielded from the wind.
Maintained lawns don’t create a suitable habitat for fleas. They’ll die in Bermuda grass, even in areas beneath trees where there’s abundant shade. The relative humidity (RH) is too low in grass, resulting in the fleas desiccating. RH must exceed 45%, even during the hottest parts of the day. Developing fleas often live under structures (e.g. decks), dense ground cover, vegetation, organic debris, branches, leaves, or loose soil.
Sprinklers & Irrigation
Most lawns are regularly watered with sprinklers. Fleas can’t survive in areas which are well irrigated, get abundant rainfall, or are poorly drained. The larvae drown in flooded areas. When soil moisture exceeds 20%, there’s a high mortality in flea larvae. The also water dissolves and washes away the fecal blood from adult fleas, which larvae require for nutrition. They’ll starve without it.
Where Fleas Live Outdoors
Fleas develop outdoors in sheltered areas where animals spend a lot of time. Specifically, places where pets go to escape the sun’s heat. Common examples include dog houses, pet shelters, crawl spaces, dense ground cover, vegetation around structures, and feral animal nests. Animals often seek shelter beneath decks or porches, and these can be flea hot-spots. Clearing away dead vegetation and debris from these areas can make them less habitable for fleas.
When the fleas reach adulthood, they may climb nearby blades of grass. The adults have a natural tendency to climb objects in their environment in order to bring them closer to a potential host.