Wait for it ... billions of Brood X cicada nymphs are emerging from the ground in 15 states — a natural phenomenon that only occurs every 17 years. After feeding off tree roots for nearly two decades, the nymphs crawl out of the soil and climb trees and other vertical structures in search of a suitable place to shed their shells. Molting takes several hours. After it has emerged from its carapace, the cicada must wait several more hours for its body and wings to harden. *** In this time-lapse fo

WATCH: Billions of cicadas are set to emerge from the ground in 15 states from Georgia to New York and over to the Mississippi River. After spending 17 years underground, the Brood X cicada nymphs will crawl out of the ground, molt into adults and mate, all in a four-week period. For some humans, like University of Maryland entomologist Mike Raupp, it offers a chance to enjoy rare delicacies like cicada cookies and tacos. | PBS NewsHour