In backyards and forests across the eastern U.S., one of nature’s greatest spectacles is underway. Although it may lack the epic majesty of the wildebeest migration in the Serengeti or the serene beauty of cherry blossom season in Japan, this event is no less awe-inspiring. I’m talking about the emergence of the Brood X cicadas.

Every 17 years the billions of constituents of Brood X tunnel up from their subterranean lairs to spend their final days partying in the sun. This generation got its start back in 2004, when Facebook existed only at Harvard University and Friends aired its last episode. The newly hatched cicada nymphs fell from the trees and burrowed into the dirt. They have been underground ever since, feeding on sap from the rootlets of grasses and trees and slowly maturing. All of that preparation has been leading up to this moment when they surface in droves—up to 1.4 million cicadas per acre—to molt into their adult form, sing their deafening love song and produce the next generation before dying just a few weeks later.