How to determine if a lice is dead or alive? - briefly
A living louse will twitch, walk, or vibrate its body when touched, and its legs and antennae will react; a dead one stays completely motionless, turns dull gray, and its body becomes limp and unresponsive.
How to determine if a lice is dead or alive? - in detail
To decide whether a louse is alive or dead, observe its behavior, physical condition, and reaction to stimuli.
A living specimen typically shows one or more of the following characteristics:
- Continuous movement, even if slow or intermittent.
- Leg articulation; legs bend and straighten rather than remain rigid.
- Ability to cling to hair shafts with a firm grip.
- Presence of a clear, glossy exoskeleton; the cuticle appears moist and reflective.
A deceased specimen usually displays:
- Complete stillness; no twitching or crawling after several minutes of observation.
- Rigid, straightened legs that cannot be flexed.
- Dull, matte coloration; the cuticle may appear desiccated or brownish.
- Detachment from hair; the body may fall off or lie loosely.
If visual assessment is inconclusive, apply a gentle tactile stimulus:
- Use a fine brush or a fingertip to lightly touch the louse’s abdomen.
- Watch for any reflex movement, such as a sudden jerk of the legs or body.
- Absence of response after repeated gentle prods indicates death.
Another reliable test involves exposure to a mild heat source:
- Place the specimen near a warm (but not scorching) surface for a few seconds.
- Live lice will exhibit rapid twitching or attempt to escape; dead ones remain inert.
Microscopic examination can provide definitive confirmation:
- Under magnification, examine the respiratory spiracles. Open spiracles suggest airflow in a living insect; closed or collapsed spiracles imply cessation of respiration.
- Check for internal gut contents; a clear, liquid-filled gut is typical of a living louse, whereas an empty or coagulated gut points to death.
Combining visual inspection, tactile response, thermal reaction, and microscopic verification yields an accurate determination of the louse’s vitality.