How can one tell that lice are dead? - briefly
A dead louse is motionless, unresponsive to touch or heat, and its body appears flattened and often darkened, showing no crawling activity.
How can one tell that lice are dead? - in detail
Physical signs indicate mortality. A lifeless louse shows no locomotion when the host’s hair is brushed or when the insect is gently prodded with a fine-toothed comb. The abdomen does not expand or contract, and there is no observable twitching of legs or antennae. Color typically darkens to a brown‑black hue; the body becomes rigid and may appear flattened compared to the glossy, tan appearance of a living specimen.
When examined under magnification, a deceased specimen lacks any rhythmic movement of the respiratory spiracles. The exoskeleton may exhibit slight desiccation, with the cuticle becoming brittle. In contrast, a live louse will display rapid, erratic leg motions and a slight tremor of the thorax.
Additional indicators include:
- Absence of response to tactile stimulation; the insect remains motionless after gentle pressure.
- No evidence of fecal pellets or feeding marks nearby, suggesting cessation of blood intake.
- Presence of a faint, sweet odor of decomposition after several hours, which does not occur with live parasites.
These observable characteristics provide reliable confirmation of death without the need for chemical tests.