The cicadas are coming Billions of periodical cicadas and their songs set to fill the spring air It has been 17 years since a set of billions of periodical cicadas emerged from their underground chambers and filled the air with boisterous buzzing and desperate mating calls. Brood X (pronounced ten), the largest emergence of the dozen periodical broods, makes its highly anticipated return just in time to shake up the spring in various regions spanning from northern Georgia all the way to Pennsylvania. “The average person only gets about four or five opportunities during their entire lifetime to experience Brood X,” said Nancy Hinkle, cicada enthusiast and professor of veterinary entomology at the University of Georgia College of Agricultural and Environmental Sciences. “It is just amazing that you have this large number of the same species of insect emerging at the same time.”