How and what does a flea feed on? - briefly
Fleas are obligate blood‑sucking parasites that feed on the plasma of mammals and birds, usually accessing capillaries near the skin surface. Frequent blood meals provide the proteins, lipids, and other nutrients necessary for their growth and reproduction.
How and what does a flea feed on? - in detail
Fleas are obligate hematophages; their mouthparts are adapted to pierce the skin of warm‑blooded hosts and ingest blood. The feeding cycle begins when a flea detects a host through visual cues, heat, carbon dioxide, and vibrations. Upon landing, the insect uses its elongated, serrated proboscis to penetrate the epidermis, locate a capillary, and draw plasma and cellular components.
The ingested meal consists primarily of:
- Plasma, which supplies sugars, proteins, and electrolytes.
- Red blood cells, providing hemoglobin and iron.
- Occasionally, leukocytes and small amounts of serum proteins.
A single adult flea can consume up to 15 µL of blood per meal, representing roughly half its body weight. After feeding, the flea regurgitates digestive enzymes into the wound to liquefy tissue, facilitating rapid uptake. The blood is stored in the midgut, where proteases, lipases, and amylases break down macromolecules. Nutrients are absorbed across the gut epithelium and transported to the fat body for storage or immediate use in egg production.
During the inter‑meal interval, the flea relies on the reserves accumulated from the previous blood meal. Females require a blood meal to initiate vitellogenesis; each engorgement can yield enough protein to develop dozens of eggs. Males also feed, but their nutritional needs are lower, supporting locomotion and mating behavior.
Environmental factors influence feeding frequency. On a suitable host, a flea may feed every 24–48 hours. In the absence of a host, the insect can survive for weeks by reducing metabolic activity and conserving stored nutrients. Temperature, humidity, and host availability determine the duration of starvation tolerance.
In summary, fleas depend exclusively on vertebrate blood, extracting plasma, red cells, and minor cellular components through a specialized proboscis. The blood provides energy, building blocks for reproduction, and the necessary substrates for metabolism, enabling the insect to complete its life cycle.