How can you determine that a nit is dead? - briefly
A dead nit looks dry, brown, and brittle, showing no movement when gently tapped or brushed. Its body lacks any visible activity or moisture.
How can you determine that a nit is dead? - in detail
A nit that is no longer viable displays several observable characteristics.
- Color change – Live nits are typically tan, gray‑brown, or amber. After death the shell turns white, chalky, or translucent.
- Surface texture – Viable nits have a smooth, glossy coating. A dead egg becomes matte, dries out, and may crack or flake.
- Shape alteration – Live nits retain a rounded, slightly domed profile. When the embryo dies, the shell often collapses, becoming flatter or irregularly warped.
- Lack of movement – Under magnification a living nit may show slow internal shifting or a faint heartbeat. No movement indicates mortality.
Microscopic examination provides additional confirmation.
- Place the specimen on a slide with a drop of saline solution.
- Observe under 40‑100× magnification.
- Look for an intact, opaque interior; a clear, empty cavity signifies an empty shell.
Chemical tests can also be employed. A drop of iodine solution reacts with protein residues in a viable nit, producing a brownish stain. Absence of staining suggests the egg is empty.
Environmental clues support the assessment. Nits found on hair that has been recently washed, dried, or exposed to high temperatures are more likely to be dead. Conversely, nits attached firmly near the scalp, especially in warm, humid conditions, are more often alive.
In summary, determining the status of a lice egg requires evaluation of color, texture, shape, movement, microscopic structure, and, when necessary, simple chemical staining. Each indicator converges on a reliable conclusion about viability.