lice are quick to adapt to changes in their environment. That’s why head lice are studied by evolutionary parasitologists.Insecticides were introduced in the 20th century as an alternative way of treating lice. Data from over-the-counter pesticide solutions in the 1980s showed high efficacy in killing head lice.
The parasitologists can observe the lice evolving over multiple generations in just a few months.
Head lice are no exception. Around the turn of the 21st century, there began to be reports that head lice were developing resistance to Lice Shampoos and similar products containing pesticides.
Since then, many studies have further documented that these “super lice” have evolved resistance to certain pesticides, and that many pesticide-based lice products are no longer achieving the high efficacy rates they once did.
Lice resistance should not be an issue for lice treatments using lice combs or dehydration (desiccation or freezing). It is highly improbable that lice will be able to evolve resistance to Cool or hot air treatments devices (which kills head lice through freezing or dehydration) because the mutations involved in resistance to pesticides would not protect lice from desiccation or freezing. Evolving “resistance” to desiccation would be akin to evolving the ability to go without water.