For as long as humans have had lice, we’ve fought hard to get rid of them. Nit combs, the fine-tooth brushes used to remove lice and their sticky eggs, have been found among the ancient remains of cultures across the globe. Today it’s estimated we spend billions of dollars each year treating infestations. So why are lice so difficult to get rid of? Nazzy Pakpour digs into these stubborn insects. Lesson by Nazzy Pakpour, directed by Oksana Kurmaz.