What are lice afraid of? - briefly
Lice are repelled by temperatures exceeding about 50 °C, which cause rapid mortality. They also avoid contact with insecticidal substances such as permethrin, dimethicone, or concentrated essential‑oil preparations.
What are lice afraid of? - in detail
Lice are highly sensitive to environmental cues that threaten their survival. Their primary aversions include extreme temperatures, chemical agents, and physical disturbances that interfere with their ability to cling to hair shafts.
Temperature extremes act as a lethal factor. Temperatures above 45 °C (113 °F) cause rapid dehydration, while exposure to below -5 °C (23 °F) leads to ice crystal formation within the insect’s body. Both conditions disrupt metabolic processes and result in mortality.
Chemical substances create a hostile environment for the parasite. Effective compounds comprise:
- Permethrin‑based insecticides, which target nervous system receptors.
- Dimethicone, a silicone oil that coats the exoskeleton, preventing respiration.
- Essential oils such as tea tree and neem, which possess repellent properties and impair feeding behavior.
Physical actions also deter lice. Frequent combing with a fine‑toothed lice comb removes individuals and eggs from the hair, reducing population density. Regular washing with hot water (≥ 60 °C) dislodges lice and destroys nits adhered to the shaft.
«Avoidance of high humidity» is another factor; lice thrive in moist conditions, but prolonged exposure to dry air (relative humidity < 30 %) desiccates them, leading to reduced mobility and death.
In summary, temperature extremes, specific insecticidal chemicals, mechanical removal, and low‑humidity environments constitute the main threats that lice instinctively avoid to preserve their existence.