What does a louse cocoon look like? - briefly
A louse cocoon is a minuscule, oval case roughly 0.5–1 mm in length, formed from a whitish, silky secretion that tightly encloses the developing nymph. Its surface appears smooth and slightly glossy, resembling a tiny, translucent grain of sand.
What does a louse cocoon look like? - in detail
A louse cocoon, also called a nits case, is a compact, oval‑shaped structure measuring approximately 0.5–0.8 mm in length and 0.2–0.3 mm in width. The outer surface appears smooth and semi‑transparent, allowing the developing nymph inside to be faintly visible as a tiny, creamy‑white body. The cocoon’s wall consists of a hardened, protein‑rich secretion that adheres firmly to hair shafts, typically positioned within 1–2 mm of the scalp where temperature is optimal for growth.
Key visual characteristics:
- Shape: elongated oval, slightly tapered at both ends.
- Color: initially pale yellow, darkening to brownish‑gray as the nymph matures.
- Texture: glossy, slightly ridged along the longitudinal axis; the ridges aid in anchoring the cocoon to the hair.
- Attachment: cement‑like base at one end grips the hair cuticle, making removal difficult without specialized tools.
- Transparency: the shell is partially translucent; when held against light, the silhouette of the nymph becomes discernible.
Internally, the cocoon encloses a single louse egg surrounded by a thin layer of fluid. As embryonic development proceeds, the egg swells, causing the cocoon to expand marginally and become more opaque. Upon hatching, the nymph chews through the shell, leaving a tiny, empty case that may remain attached to the hair for several days before falling off.