What do lice excrement look like? - briefly
Lice droppings appear as minute, dark specks—typically black or brown—that look like tiny pepper grains on hair shafts or fabric. They are dry, crumbly particles easily mistaken for lint.
What do lice excrement look like? - in detail
Lice feces are tiny, dark specks measuring 0.1–0.3 mm in diameter. Under a magnifying lens they appear as matte, granular particles, often described as “pinhead‑size” or “caviar‑like.” The coloration ranges from deep brown to black, occasionally showing a reddish hue when fresh blood is present in the waste. Dried deposits become slightly raised, forming a rough texture that can be felt on hair shafts or scalp skin.
Typical locations include:
- The base of hair strands, especially near the scalp where adult lice congregate.
- The inter‑follicular spaces of the head, where nits are attached.
- The neck and behind the ears, areas that lice frequently traverse.
Composition consists primarily of digested hemoglobin, bacterial remnants, and undigested keratin. The presence of hemoglobin imparts the characteristic dark color, while bacterial content may give a faint odor detectable only at close range.
Microscopic examination reveals:
- Oval or irregular outlines, lacking a defined cell wall.
- A granular interior with occasional visible blood cells.
- A surface that reflects little light, confirming the matte appearance.
Differences among species:
- Pediculus humanus capitis (head lice) produce the smallest, darkest particles.
- Pediculus humanus corporis (body lice) excrete slightly larger, more yellow‑brown specks due to higher fat content in their diet.
- Pthirus pubis (pubic lice) generate coarser, reddish‑brown fragments because of their thicker exoskeleton.
Detection methods:
- Use a fine‑toothed comb on damp hair; excrement adheres to the comb teeth and becomes visible against a white background.
- Apply a translucent liquid (e.g., vinegar or alcohol) to the scalp; fecal particles dissolve partially, revealing a faint black stain.
- Conduct a slide‑mount microscopy of hair samples; fecal material appears as distinct, non‑refractive dots amidst hair shafts.
In clinical practice, the presence of these dark specks, especially when paired with live lice or nits, confirms an active infestation. Cleaning the environment with hot water, steam, or a 0.5 % bleach solution removes residual waste and reduces the risk of re‑infestation.