Medicated Shampoos
Regular shampoos may be unable to do the trick, so it is advisable to use medicated shampoos to get rid of the insects. In some cases, this may prove ineffective because lice have high resistance and may remain on the scalp. It is advisable to combine washing with combing patiently for up to several days or a week to remove these insects completely.
References:
[1] https://www.healthline.com/health/lice/where-do-lice-come-from#:~:text=The%20microscopic%20insects%20live%20in,long%20away%20from%20their%20host.
[2] https://kidshealth.org/en/parents/head-lice.html#:~:text=Head%20lice%20are%20a%20common,they%20don’t%20spread%20disease.
[3] https://www.medicinenet.com/head_lice/article.htm
[4] https://www.aafp.org/afp/2007/0315/p910.html
[5] https://www.racgp.org.au/afp/2013/march/wet-combing/