Where Do Head Lice Come From Originally?

Head lice are a parasite found in human hair and scalps. They feed on the blood of their host. When they feed, the lice lay eggs known as nits. These eggs are attached to the hair shafts at the surface of the scalp. Children are most susceptible to catching head lice, since they frequently share hair and other items.

While we are not sure how these creatures got to our heads, they were originally found on the heads of the Shuar/Jivaro people, who lived in the highlands of northern Peru and eastern Ecuador. These individuals had a close relationship with other humans and so, the parasites they carried spread to them.

Head lice have been around for thousands of years. In fact, Egyptian mummies have been discovered with lice nits. They likely developed from body lice and then evolved into head lice. These parasites feed on the blood of their host, and are transmitted through close contact. In order for a non-infested person to contract head lice, they must come into head-to-head contact with the infected person. In addition, sharing clothing and personal items can spread the parasite quickly.

Using DNA from the mitochondria of head lice nits has helped researchers trace the ancestry of lice to two different groups, Clade A and Clade B, which split about 800,000 to one million years ago. Scientists believe the findings are significant for understanding the evolution of humans. Because lice only feed on human blood, their DNA is relatively pure, allowing scientists to examine the roots of the modern human species.