How do lice spread on a child's head? - briefly
Lice transfer primarily via direct head‑to‑head contact or by sharing items that touch hair, such as hats, combs, or hair ties. They crawl onto a new host; they do not jump or fly.
How do lice spread on a child's head? - in detail
Lice move from one child's scalp to another primarily through direct head‑to‑head contact. The insects cling to hair shafts and can crawl across the hairline within seconds of physical interaction. This mode of transmission accounts for the majority of infestations in preschool and elementary settings, where children frequently play in close proximity.
Secondary pathways involve shared personal objects that come into contact with hair. Items such as combs, brushes, hats, hair ties, helmets, and earbuds can retain live insects or their eggs. When another child uses the contaminated object, lice transfer to the new host. The risk increases if the objects are not cleaned regularly.
Fomites—bedding, pillows, towels, and clothing—can also serve as reservoirs. Lice survive off the scalp for up to 48 hours, allowing them to migrate from contaminated fabrics to a new wearer. Although less common than direct contact, this route contributes to outbreaks in households and daycare centers.
Key factors that amplify spread include:
- Close physical play (e.g., group games, hugging)
- Frequent sharing of hair accessories
- Overcrowded environments with limited personal space
- Inadequate laundering of clothing and bedding
- Delayed detection and treatment of an existing infestation
Understanding these mechanisms enables effective control strategies, such as minimizing head contact, avoiding shared grooming tools, and maintaining regular washing of personal textiles.