How do lice, fleas, and bedbugs look? - briefly
Lice are tiny, wing‑less insects about 2–4 mm long, grayish‑white, with a flattened, elongated body and visible egg shells (nits) attached to hair shafts; fleas are slightly larger (1–4 mm), dark brown, laterally flattened, and equipped with powerful hind legs for jumping; bedbugs are oval, flat, reddish‑brown bugs roughly 4–5 mm in length, becoming swollen and lighter‑colored after feeding.
How do lice, fleas, and bedbugs look? - in detail
Lice, fleas, and bedbugs are three distinct ectoparasites, each with characteristic morphology that aids identification.
Lice are small, wingless insects measuring 2–4 mm in length. Their bodies are laterally compressed, giving a flattened appearance that facilitates movement through hair shafts. The head is small with prominent, forward‑facing antennae. Mouthparts form a piercing‑sucking apparatus adapted for feeding on blood. Color varies from gray‑white in nymphs to darker brown in adults. Legs end in sharp claws that grasp individual hairs.
Fleats are slightly larger, ranging from 1.5 to 3.5 mm. Their bodies are laterally flattened and covered with a hard exoskeleton that appears brown to reddish‑brown. The thorax bears long, powerful hind legs adapted for jumping; each leg ends in a tiny bristle that anchors to host fur. Antennae are short and concealed beneath the head capsule. The abdomen is segmented, often showing a light‑colored band near the posterior edge.
Bedbugs measure 4–5 mm when unfed, expanding to 7 mm after a blood meal. Their bodies are oval, dorsoventrally flattened, and display a reddish‑brown hue that darkens after feeding. The head is short, with a beak‑like proboscis used for piercing skin. Legs are short, each ending in a tiny claw. The dorsal surface bears fine hairs and a faintly visible line separating the thorax from the abdomen. After engorgement, the abdomen becomes markedly distended and more opaque.
Key visual distinctions:
- Body shape: lice – elongated and flattened; fleas – laterally compressed with pronounced hind legs; bedbugs – oval and dorsoventrally flattened.
- Size range: lice 2–4 mm; fleas 1.5–3.5 mm; bedbugs 4–7 mm (fed).
- Coloration: lice – gray‑white to brown; fleas – brown to reddish‑brown; bedbugs – reddish‑brown, darkening after feeding.
- Locomotive adaptations: lice – claws for hair; fleas – powerful jumping legs; bedbugs – limited mobility, rely on crawling.
These morphological features enable reliable differentiation during visual inspection or microscopic examination.