(NEXSTAR) – So many cicadas have emerged from their long slumber, singing loud and peeing into the wind, that this phenomenon has been dubbed a “cicada-geddon.”

We have two broods of cicadas to thank – Brood XIX and Brood XIII – which have swarmed a large area of the eastern U.S. It’s very hard to take stock of the number of insects involved, experts say, but they estimate it’s in the hundreds of trillions.

The reason 2024 is so special is because it’s a year of co-emergence for two very large broods that are geographically adjacent. Periodic cicada species stay buried underground for long stretches of time, and only emerge every 13 or 17 years (depending on the brood) when the ground warms up to 64 degrees.

These two broods haven’t synced up since 1803, and won’t emerge at the same time again for another 221 years.

But another cicada-geddon is scheduled to hit the U.S. sooner than that. An even bigger, adjacent joint-emergence will happen when the two largest broods, XIX and XIV, come out together in 2076.

“That is the cicada-palooza,” University of Connecticut cicada expert John Cooley told the Associated Press.

The 2076 co-emergence will cover a large area over 16 states.

Between now and 2076, there will be several more co-emergences – in 2037, 2041 and 2050, for example – but they won’t be geographically adjacent. When they’re separated by more space, the impact is a bit more tame – though still noticeable.

“Periodic cicadas don’t do subtle,” Cooley said. Their collective song can grow to be as loud as a jet engine. “It’s up in the 110 decibel range. It’d be like putting your head next to a jet. It is painful.”

If you’re currently plagued by the roaring sounds of mating cicadas, relief is on the way. Cicadas stay active for about four to six weeks after they emerge.

The Associated Press contributed to this report.