What do live lice look like? - briefly
Living lice are tiny, wingless insects about 2–4 mm long, with a flattened, elongated body that is gray‑brown to tan in color. They possess six short legs ending in clawed tarsi that firmly grasp hair shafts.
What do live lice look like? - in detail
Live lice are small, wing‑less insects with a flattened, elongated body that allows them to move through hair shafts. An adult typically measures 2–4 mm in length; females are slightly larger than males. Their coloration ranges from gray‑white to light brown, becoming darker after a blood meal. The exoskeleton is smooth and slightly glossy, lacking any obvious segmentation beyond the head, thorax, and abdomen.
The head bears a pair of compound eyes positioned laterally and a pair of short antennae composed of five segments. Mouthparts form a piercing‑sucking proboscis adapted for feeding on blood. Six legs emerge from the thorax, each ending in claw‑like tarsal hooks that grip individual hair strands. The legs are short, with three segments (coxa, trochanter‑femur, tibia). The abdomen consists of seven visible segments, each bearing tiny bristles (setae) that aid in sensory perception.
Nymphal stages resemble adults but are smaller (1–2 mm) and paler, lacking the darker post‑feeding coloration. They undergo three molts before reaching maturity, and each instar retains the same basic morphology—head, antennae, eyes, legs, and segmented abdomen.
Eggs (nits) are oval, 0.8 mm long, and firmly attached to hair shafts near the scalp with a cement‑like substance. They appear white or translucent and are often mistaken for dandruff, but their shell is rigid and slightly curved to match the hair’s contour.
Head lice, body lice, and pubic lice share the general body plan described above, differing mainly in size (pubic lice are larger, 2–4 mm), coloration (pubic lice are darker, reddish‑brown), and the shape of the abdomen (pubic lice have a broader, more rounded abdomen). Body lice are similar in size to head lice but have a slightly longer abdomen and are adapted to clothing rather than hair.