Is it true that lice live on a person? - briefly
Yes, head lice (Pediculus humanus capitis) reside on the scalp and feed on human blood. They die within 24–48 hours when removed from a host.
Is it true that lice live on a person? - in detail
Lice are obligate ectoparasites that complete their entire life cycle on a human host. Adult females lay eggs (nits) attached to hair shafts near the scalp, eyebrows, or body hair, depending on the species. The eggs hatch in 7–10 days, releasing nymphs that molt three times before reaching maturity. Each adult can survive for several weeks, feeding several times daily on blood.
Key points about their habitation:
- Head lice (Pediculus humanus capitis): reside on the scalp, preferring the nape of the neck and behind the ears. They move quickly through hair but cannot survive long on clothing or furniture.
- Body lice (Pediculus humanus corporis): live in the seams of clothing, descending to the skin only to feed. They are associated with poor hygiene and crowded conditions.
- Pubic lice (Pthirus pubis): inhabit coarse hair of the genital region, but may also be found on chest, armpits, and facial hair. They are transmitted primarily through sexual contact.
Survival off the host is limited. Without a blood meal, nymphs die within 24–48 hours, and adults survive no more than a few days. Environmental factors such as temperature and humidity influence viability, but the species are adapted to the microclimate of human skin and hair.
Control measures target the parasite’s dependence on the host:
- Chemical or physical treatments that kill adults and nits.
- Thorough washing of clothing, bedding, and personal items at temperatures above 50 °C or using dry heat for at least 30 minutes.
- Regular combing with fine-toothed lice combs to remove nits from hair shafts.
In summary, lice do not merely visit humans; they inhabit the body or clothing of the host throughout their developmental stages, relying on continuous blood feeding for survival. Their existence is confined to the human environment, and they cannot persist independently for more than a few days.