How can you distinguish a head louse from a clothing louse? - briefly
«Head lice» possess a compact, rounded body and clawed legs adapted to grasp hair shafts, whereas «clothing lice» are larger, flatter, and lay eggs in garment seams. The former feeds directly on scalp blood, the latter on skin debris and clothing.
How can you distinguish a head louse from a clothing louse? - in detail
Head lice (Pediculus humanus capitis) and clothing lice (Pediculus humanus humanus) differ in several observable characteristics.
- Size: both species measure about 2–4 mm, but clothing lice are slightly broader, often appearing more robust.
- Body shape: head lice possess a more tapered abdomen, whereas clothing lice have a rounded abdomen that expands toward the posterior.
- Coloration: head lice are generally lighter, ranging from gray‑white to tan; clothing lice tend toward a darker gray.
- Head: head lice have a shorter, less pronounced head with a blunt anterior margin; clothing lice exhibit a longer, more pointed head.
Habitat provides additional clues. Head lice remain on the scalp, clinging to hair shafts near the scalp surface. Clothing lice reside in seams and folds of garments, especially in the area of the waist, armpits, and groin, and only move to the body to feed.
Egg placement distinguishes the two. Head‑lice nits are firmly attached to hair shafts about 1 mm from the scalp, often at an angle that makes them difficult to dislodge. Clothing‑lice nits are deposited on fabric fibers, particularly in seams, and are less firmly attached, allowing easier removal with a fine‑toothed comb or by laundering.
Feeding behavior also varies. Both species feed on human blood, but head lice feed continuously while attached to the scalp, causing itching localized to the head. Clothing lice feed intermittently, typically at night, and may cause generalized itching and a rash on covered skin.
Mobility differences are evident under magnification. Head lice move rapidly through hair, using their claws to grasp each strand. Clothing lice exhibit slower movement, preferring to crawl along fabric fibers and only climb onto the host when feeding.
In summary, identification relies on morphological cues (body shape, head length, coloration), ecological context (scalp versus clothing), egg attachment sites, and feeding patterns. Accurate differentiation guides appropriate treatment, such as topical pediculicides for scalp infestation and thorough laundering for garment‑associated infestation.