Flea

Natural Habitat

Fleas are found worldwide and can inhabit a wide range of environments where their hosts reside. They are commonly found in carpets, bedding, pet sleeping areas, cracks in floors, and furniture. Outdoors, they can live in shaded, moist areas where animals rest, such as under bushes or decks. They prefer warm, humid conditions.

Diet & Feeding

Adult fleas are obligate hematophages, meaning they feed exclusively on the blood of their warm-blooded hosts (mammals and birds). Flea larvae, unlike adults, do not feed on blood; they consume organic debris, including skin flakes, hair, and the blood-rich feces of adult fleas (often called 'flea dirt').

Behavior Patterns

Fleas are ectoparasites, meaning they live on the outside of their hosts. They are known for their ability to jump significant distances relative to their size, aided by specialized resilin pads in their legs. Adult fleas spend most of their lives on a host, feeding on blood. Females lay eggs (up to 50 per day) that typically fall off the host into the environment. Larvae hatch from the eggs and feed on organic debris, including adult flea feces. They then pupate in a cocoon, from which adult fleas emerge when they detect a potential host nearby (e.g., through vibrations, CO2, or heat). The entire life cycle can take as little as 2-3 weeks under optimal conditions.

Risks & Benefits

Potential risks include causing itchy and irritating bites in humans and animals, leading to allergic reactions (flea allergy dermatitis in pets) and secondary skin infections from scratching. Fleas can also transmit diseases, such as tapeworm (Dipylidium caninum) to pets and sometimes humans, and historically, Yersinia pestis (plague) and Rickettsia typhi (murine typhus). Benefits are negligible from a human perspective; they are primarily known as pests and disease vectors.

Identified on: 9/4/2025