How do all types of lice look? - briefly
Head lice are tiny, wingless insects about 2–3 mm long, gray‑white with a flattened, elongated body; body lice are slightly larger (3–4 mm), reddish‑brown, and more robust. Pubic (crab) lice are broader, crab‑shaped, 1–2 mm in size, and dark brown to reddish in color.
How do all types of lice look? - in detail
Lice are obligate ectoparasites with a body divided into head, thorax and abdomen, six jointed legs, no wings, short antennae and compound eyes. All species possess a dorsally flattened, elongated form and a chitinous exoskeleton that provides protection and rigidity.
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Head lice (Pediculus humanus capitis)
Length: 2–3 mm.
Color: gray‑white, becoming darker after feeding.
Body: slender, slightly tapered toward the posterior.
Legs: all six are similar, each ending in a claw adapted to grasp hair shafts.
Eyes: visible, positioned laterally on the head. -
Body lice (Pediculus humanus corporis)
Length: 3–4 mm, marginally larger than head lice.
Color: similar gray‑white, darkening after engorgement.
Body: more robust, abdomen slightly broader.
Legs: longer than those of head lice, facilitating movement across clothing fibers.
Antennae: longer, aiding navigation on cloth surfaces. -
Pubic (crab) lice (Pthirus pubis)
Length: 1–2 mm.
Color: dark brown to black.
Body: crab‑shaped, broader and flatter than head or body lice.
Legs: front pair markedly shorter, middle and hind pairs longer, ending in strong claws for gripping coarse hair.
Eyes: reduced, often not visible. -
Bird lice (various families, e.g., Menopon, Philopterus)
Length: 1–3 mm.
Color: ranges from pale cream to brown, often matching host plumage.
Body: highly flattened, facilitating movement between feathers.
Legs: short, with robust claws for clinging to feather shafts.
Mouthparts: chewing type, adapted for feeding on skin debris and feathers. -
Animal chewing lice (order Phthiraptera, families such as Linognathus, Haematopinus)
Length: 2–5 mm, depending on host species.
Color: varies from light gray to dark brown.
Body: flattened, sometimes with a granular surface.
Legs: three pairs, each ending in a claw; front legs often larger for grasping hair.
Mouthparts: mandibles for chewing skin, fur, or feather fragments. -
Animal sucking lice (families Anoplura, e.g., Pediculus, Haematopinus)
Length: 2–5 mm.
Color: typically brown to reddish after blood meals.
Body: elongated, less flattened than chewing lice.
Legs: all six are similar, ending in claws for attachment to hair.
Mouthparts: piercing‑sucking apparatus for blood extraction.
Overall, lice share a compact, wingless morphology but differ markedly in size, body shape, leg proportion and mouthpart specialization, reflecting adaptation to distinct host habitats and feeding strategies.