What do fleas and lice look like on people? - briefly
Fleas are 1–3 mm dark brown or black insects that move quickly on skin or clothing and leave small, itchy bite spots. Lice are 2–4 mm pale‑gray or tan, wing‑less parasites that cling to hair shafts, with their eggs (nits) appearing as tiny white or yellowish ovals attached close to the scalp.
What do fleas and lice look like on people? - in detail
Fleas are small, laterally flattened insects measuring 1–4 mm in length. Their bodies are dark brown to reddish‑black, with a hard exoskeleton that gives a glossy appearance. Under a magnifying lens, the head appears narrow with long, powerful hind legs adapted for jumping. On a human host, fleas may be seen moving quickly across the skin, especially in the groin, waistline, and between the thighs. They leave tiny, pinpoint puncture wounds that bleed slightly and become red, itchy papules. In heavy infestations, clusters of flea feces—dark specks resembling pepper—accumulate on clothing and skin folds.
Head lice (Pediculus humanus capitis) are about 2–4 mm long, elongated, and gray‑white in color. The body is soft, lacking a hard exoskeleton, and the three‑segmented abdomen is visible through the transparent cuticle. Lice cling to hair shafts close to the scalp, especially behind the ears and at the nape of the neck. They are most often detected by feeling a moving, crawling sensation or by finding live insects on the hair. Egg cases (nits) appear as tiny, oval, beige or yellowish shells firmly attached to the hair shaft at a 45‑degree angle; they are not easily brushed away. Scratching can cause small, red, inflamed spots where the lice bite to feed on blood.
Body lice (Pediculus humanus corporis) are similar in size and color to head lice but reside in the seams of clothing rather than on hair. They lay eggs on fabric, and their nits are less conspicuous because they are not attached to hair. Infestations produce intense itching and a rash of small, red papules, often in areas where clothing fits tightly, such as the waist, armpits, and buttocks.
Key visual differences:
- Size: Both groups are 1–4 mm; fleas are slightly broader.
- Body shape: Fleas are laterally flattened with a hard exoskeleton; lice are elongated with a soft, translucent body.
- Color: Fleas are dark brown to black; lice are gray‑white.
- Location on host: Fleas favor skin folds and warm, moist areas; head lice inhabit scalp hair; body lice hide in clothing seams.
- Egg attachment: Flea eggs are not attached to hair; lice nits are firmly glued to hair shafts at an angle.
Recognizing these characteristics enables accurate identification and appropriate treatment of each parasite.