Head lice are human parasites and have probably been around since the beginning of time. They have found desiccated (dried up) head lice and their eggs (nits) on the hair and scalps of Egyptian mummies and Cleopatra is said to have a golden "lice" comb. The scientific version indicates the DNA from mitochondria of head lice cells collected form lice around the world have traced lice back to a common lineage about 2 million years ago. Scientist believe due to the relationship with humans lice can provide important information about human evolution.
Lice continue to evolve and many traditional OTC lice treatment products using Permethrin are less effective as the bugs have developed a resistance to them.