What are lice eaten from? - briefly
Lice obtain nutrition by piercing the skin of their host and sucking blood. They feed primarily on humans and other warm‑blooded mammals.
What are lice eaten from? - in detail
Lice are obligate ectoparasites that obtain nutrition exclusively from the body of their human host. Their mouthparts are adapted to pierce the epidermis and draw liquid blood, which supplies all essential nutrients. The primary source is capillary blood from the scalp in the case of head lice, and from the body surface in the case of body lice. These insects do not consume hair, skin debris, or sebum as a regular part of their diet; any incidental ingestion of epithelial cells occurs only when the feeding site is disrupted.
Feeding occurs several times a day. Each session lasts a few minutes, during which the insect injects saliva containing anticoagulants to maintain blood flow. The volume of blood taken per meal is minute—typically 0.5–1.0 µL—yet it is sufficient to sustain the insect for several hours. Between meals, lice rest on the host’s hair or clothing, where they remain attached by claws.
The dependence on blood imposes strict ecological limits. Lice cannot survive more than 24–48 hours without a host, and prolonged deprivation leads to rapid mortality. Environmental conditions such as temperature and humidity influence feeding frequency, but the nutritional requirement remains unchanged: liquid blood from the host’s microvasculature.
In summary, lice derive all sustenance from host blood accessed through specialized mouthparts; they do not rely on other bodily secretions or external food sources.