Head lice are disgusting parasites that we have never been able to eradicate. We all remember the head lice checks in elementary school. They’ve been following us around for centuries. Now, mummified head lice are helping us to understand ancient migrations. Researches were able to extract DNA from lice found on two pre-Columbian Peruvian mummies (about 1,000 years old). The DNA allowed researchers to establish that the lice have been riding along on human hosts for as early as 15,000 years ago. The DNA matches that of the most common type of louse and is believed to have traveled all the way from Africa.

This lets Columbus of the hook. Typhus, carried by head lice, is one of the many diseases previously thought to have been introduced by the Europeans. Though we can still thank Columbus for the measles.