How quickly do lice migrate? - briefly
Adult head lice crawl at about 1 cm per minute, moving only a few centimeters in an hour. Their spread therefore depends on direct host‑to‑host contact rather than rapid, independent migration.
How quickly do lice migrate? - in detail
Lice move primarily by crawling, not by flying or swimming. An adult head louse covers roughly 1–2 cm per minute on a human scalp, allowing it to travel the entire head surface within a few hours. Nymphs crawl at a slightly slower rate, about 0.5–1 cm per minute. Movement between hosts occurs only when a louse is transferred manually (e.g., through direct head‑to‑head contact) or via contaminated objects such as combs, hats, or bedding. The transfer itself is instantaneous; the louse does not travel independently over distance.
Key factors influencing travel speed:
- Body temperature: Higher temperatures increase metabolic activity, marginally accelerating crawling speed.
- Hair density: Dense hair provides more pathways, enabling faster navigation across the scalp.
- Age of the louse: Mature adults move faster than freshly hatched nymphs.
- Host behavior: Frequent head contact among individuals creates immediate opportunities for host switching.
Overall, a louse can explore an entire scalp within a few hours, while inter‑host migration depends entirely on direct contact or contaminated items and therefore lacks a measurable travel time independent of human interaction.