How do lice larvae look on humans? - briefly
Lice nymphs are minute, approximately 0.8–1 mm long, translucent to whitish, and cling to hair shafts close to the scalp. They move slowly and may be seen as tiny, mobile specks near the base of each hair.
How do lice larvae look on humans? - in detail
Lice nymphs, the immature stage of head‑lice (Pediculus humanus capitis), are easily recognizable when they inhabit a human scalp. They measure approximately 0.8 mm in length, about half the size of an adult. Their bodies are elongated, slightly flattened, and covered with fine, translucent cuticle that often appears pale gray or light brown. Under magnification, the three pairs of legs are visible; each leg ends in a claw that grips hair shafts.
Key visual characteristics include:
- Color: translucent to light brown; may become darker after a blood meal.
- Shape: oval, tapering slightly toward the posterior; abdomen less rounded than that of an adult.
- Eyes: rudimentary, often indistinct; not prominent.
- Mouthparts: small, piercing‑sucking apparatus concealed beneath the head capsule.
- Movement: rapid, darting motions along hair shafts; capable of climbing quickly.
Nymphs are typically found close to the scalp where temperature and humidity are optimal. They remain attached to individual hair strands, usually within 1 cm of the scalp surface, and can be observed crawling or resting on the hair shaft. After feeding, a nymph swells slightly, gaining a pinkish hue due to engorgement. This change is temporary; the insect returns to its translucent coloration as digestion proceeds.