What do lice and nits feed on? - briefly
Adult lice and their nymphs feed on the host’s blood, piercing the skin or scalp to obtain nutrients. The eggs, or nits, contain yolk reserves supplied by the adult female and do not feed independently.
What do lice and nits feed on? - in detail
Lice are obligate hematophagous ectoparasites. Their mouthparts form a piercing‑sucking apparatus that penetrates the epidermis to access capillary blood. The primary source of nourishment is human blood, which supplies the protein, iron, and other nutrients required for growth, reproduction, and metabolic activity. Head and body lice feed several times a day, each bout lasting a few minutes, and ingest only a few microliters per session—enough to sustain the insect until the next meal.
The egg stage, commonly called a nit, does not ingest external material. Nits contain a yolk sac that provides all nutrients needed for embryonic development. This internal reserve supports the embryo through the approximately 7‑10 day incubation period, after which the nymph emerges and immediately begins blood feeding.
Key points about the feeding biology:
- Adult and nymph stages: blood‑based diet; repeated short meals; reliance on host’s scalp, body hair, or pubic hair for attachment.
- Egg stage: no external feeding; nutrient supply is endogenous yolk.
- Nutrient composition: blood delivers hemoglobin (iron source), plasma proteins, and carbohydrates essential for molting and egg production.
- Feeding frequency: adults may take 4–5 meals per day; each meal provides roughly 0.5–1 µL of blood.
- Environmental requirements: temperature around 30 °C and high humidity facilitate feeding efficiency and egg viability.
Understanding these dietary specifics is critical for developing control strategies that interrupt blood access or compromise egg development.