Where do lice live and what do they eat? - briefly
Lice reside on the hair, fur, or feathers of their host, attaching themselves close to the skin. They survive by piercing the skin and drinking the host’s blood.
Where do lice live and what do they eat? - in detail
Lice are obligate ectoparasites that complete their entire life cycle on a host organism. Adult females lay eggs (nits) on hair shafts or feathers, and the emerging nymphs remain attached to the same surface until maturation. Consequently, the preferred environment is a warm, protected niche that supplies continuous access to food.
Typical locations include:
- Scalp hair of humans, where head lice (Pediculus humanus capitis) reside close to the skin.
- Body hair and clothing seams, inhabited by body lice (Pediculus humanus corporis) that lay eggs on fabric.
- Pubic region, occupied by crab lice (Pthirus pubis) that cling to coarse hair.
- Feathers of birds, where avian lice (e.g., Menacanthus spp.) dwell among the plumage.
- Fur of mammals such as rodents, dogs, or livestock, providing shelter for species adapted to those hosts.
Feeding behavior is uniform across most lice species: they ingest blood or, in some cases, skin debris. The process involves piercing the host’s epidermis with a specialized, saw‑toothed mandible. Key points about nutrition:
- Head and body lice extract small quantities of blood several times a day, each meal lasting a few minutes.
- Pubic lice feed on blood from the skin surface of the genital area, requiring fewer feeds due to the richer vascular supply.
- Avian lice primarily consume feather keratin and skin flakes, supplementing with blood when available.
- The amount of blood ingested is sufficient to sustain development from egg to adult within 7–14 days, depending on temperature and host availability.
Environmental constraints limit lice distribution. They cannot survive more than 24–48 hours off a suitable host because they lack the ability to regulate temperature and humidity independently. This short off‑host survival period explains why infestations are confined to areas where hosts congregate, such as schools, households, or animal shelters.