Most flea cocoons live within carpeting. They can also be found on pet bedding or upholstered furniture. Outdoors, the cocoons may develop in dog houses, dense vegetation, or moist, shaded soil.
Cocoons are Spun in the Larval Environment
Once flea larvae are fully grown, they’ll move to an undisturbed location to spin a cocoon. Within the larval environment, the cocoon becomes camouflaged with surrounding debris. Sometimes fleas pupate without cocoons. ‘Naked pupae’ develop when there isn’t a nearby physical object or vertical surface to attach silk threads to.
Where Flea Cocoons Reside
Cocoons develop in same areas as eggs and larvae. Viable zones aren’t widespread around homes. To survive and reach adulthood, eggs must fall into warm, humid, protected microhabitats which contain plenty of larval food.
Most fleas develop indoors. 83% of immature fleas will be found within carpeting. Flea larvae move away from light and towards food. As a result, they live at the base of carpets. When forming a cocoon, their sticky silk gets bound in the carpet fibers. Within the carpeting, fleas cocoons are difficult to detect and are protected from insecticides. This is especially true for cocoons behind or underneath furniture.
Where the cocoons are found in the carpeting depends upon the type of carpeting. Most cocoons are found at the bottom of nylon loop and wool loop carpets. However, more cocoons are found at the top of nylon saxony and nylon contract carpets.
Along with carpeting, flea cocoons can be found indoors on upholstered furniture and animal bedding. Less common areas to find cocoon are hallways that get a lot of traffic, and wood and tile floors.
Immature fleas are less likely to be found outdoors. They’ll die in open, sun-exposed areas. Viable development zones must have high humidity, shade and wind protection. Areas in yards where flea cocoons can be found include in vegetation, shaded soil, dog houses, crawl spaces, and under rocks. Flea larvae live within the first couple centimeters of soil or on the surface. So the cocoons won’t be buried.
Areas that get too wet won’t support development (e.g. near sprinklers). Flea larvae drown in water. Additionally, the water will dissolve and wash away the adult feces which larvae require for food. Cocoons are more resistant to drowning, but they must survive to reach this stage.