After spending more than a decade underground, roughly a trillion noisy, red-eyed cicadas are beginning to emerge from the earth. This year, the Great Southern Brood, which comes out every 13 years and has already been spotted in Georgia, is expected to converge in the Midwest with the Northern Illinois Brood, which emerges every 17 years.
No one can explain for sure how the cicadas know when to come out en masse, or why they do. But when the two broods arrive in full force this spring, it will be the first time that they have shown up together since Thomas Jefferson was president.
New York Times