How do lice get onto the head? - briefly
Lice reach a scalp via direct head‑to‑head contact or by crawling from contaminated objects such as combs, hats, or bedding. They do not jump or fly; they move by crawling.
How do lice get onto the head? - in detail
Lice reach a new host primarily through direct head‑to‑head contact. When an infested person’s hair brushes against another’s, adult insects and newly hatched nymphs crawl onto the clean scalp within seconds. This mode accounts for the vast majority of infestations, especially among school‑aged children who frequently engage in close physical interaction.
Secondary routes involve shared personal items that have recently contacted an infested head. Items such as combs, brushes, hair accessories, hats, helmets, scarves, and pillowcases can retain live lice or viable eggs for several hours. If another individual uses these objects before they are cleaned, the parasites can transfer onto the new host’s hair.
Lice also survive briefly on inanimate surfaces under favorable conditions—moderate temperature (20‑30 °C) and high humidity (≥50 %). Although they cannot live longer than 24–48 hours without a host, accidental contact with contaminated furniture or clothing may lead to temporary attachment and subsequent migration to the scalp.
Key factors that increase the likelihood of acquisition include:
- Close, prolonged contact in crowded settings (classrooms, sports teams, camps).
- Sharing of headgear or grooming tools without disinfection.
- Presence of an existing infestation in the household or community.
- Inadequate hygiene practices that allow lice to remain on personal items.
Understanding these pathways helps target preventive measures: minimizing head‑to‑head contact, avoiding the exchange of hair accessories, and regularly cleaning or isolating items that may harbor parasites.