Nineteen states are going to hear a whole lot of buzzing this spring and summer when cicadas emerge during what's being described as a once-in-a-lifetime event.
Two different cicada broods, one on a 13-year cycle and another on a 17-year cycle, are both set to hatch this year -- an incredibly rare event that only happens once every 221 years. According to ScienceAlert.com, the phenomenon last occurred in 1803 and won't happen again until 2245.
These aren't the typical cicadas that come every year. They're periodical cicadas that have been hiding underground for more than a decade.
The cicadas will simultaneously surface across several Midwestern and southern states, but most heavily in Illinois and Missouri, according to reports.
Brood XIX, which last appeared in 2011, is expected to emerge in 14 states:
Alabama, Arkansas, Georgia, Illinois, Indiana, Kentucky, Louisiana, Missouri, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee and Virginia.
Brood XIII, which last appeared in 2007, is expected to emerge in Iowa, Wisconsin, Illinois, Indiana and possibly Michigan.
They'll begin to appear in mid-May through late June, once the soil reaches a temperature of around 64 degrees Fahrenheit, and will be mostly gone by July 1.
The insects will rise by the billions, experts predict.
As the cicadas shed their skins, leaving them behind on trees and elsewhere, they mature into adults. Then comes the unmistakable soundtrack: an incessant, shrieking buzz as males try to attract a mate by making a lot of noise. The buzz can reach up to 100 decibels — about as loud as a motorcycle or jackhammer, NBC News reported.
The females will lay their eggs inside tiny holes in tree and shrub branches and after about five-to-six weeks of life above ground, all the adults will die. The eggs hatch after six to 10 weeks and nymphs burrow into the soil where they begin their life cycle underground, waiting to make an appearance roughly two decades from now.