Head lice taken from 1,000-year-old mummies in Peru support the idea that the little creatures accompanied humans on their first migration out of Africa, 100,000 years ago, researchers reported Wednesday.

Genetic tests showed the lice are nearly identical to strains found around the world that have been dated to when humans first began to colonize the rest of the world.

"It tells us that this genetic type got around the globe right as humans spread and migrated around the globe," said David Reed of the University of Florida, who worked on the study.