According to the World Health Organization, head lice is the most prevalent human parasitic infestation in the USA and Europe . Head lice are parasitic insects that survive by feeding off human blood and can be found in the hair, eyebrows and eyelashes. Lice are extremely contagious and are spread by close person-to-person contact, either directly or indirectly. Direct contact with an infested person can lead to an infestation as well as contact with an infested person’s belongings such as coats, hats, pillows and brushes.

Symptoms include a tickling feeling in the hair, frequent itching and sores on the scalp from scratching. Lice are easiest to detect at the neckline and behind the ears. There are three forms of lice: nits (eggs), nymphs and adults. An adult louse is about the size of a sesame seed and can survive on a human for up to 30 days. They usually cannot survive off the host for more than 24 hours.