Sometime late this spring, under a cloak of darkness, a horde of bulbous-eyed insects will emerge from underground, where they’ve spent most of their lives feeding from the sap of tree roots. They will scurry up the first trees they can find, leaving behind their exoskeletons as they molt, shedding old shells as they develop those trademark wings.

The males will soon begin to emit a buzzing noise, before the female bugs join them in a chorus of clicks—a cacophony of mating sounds that will swell in a matter of days.

This unique natural symphony will serve as an unmissable signal that two broods of cicadas have emerged from belowground for a rare, dually-occurring return to the world above. That sound can be so loud. The noise can reach 100 decibels. About the level of a jet engine.

Beginning anytime between late April to June, the two broods will emerge in 17 states spanning the Southeast to the Midwest. It will be a bigger year than most. This is a magical event.

It has been 221 years since these particular broods last emerged together. It was 1803 the last time this phenomena occurred, when Thomas Jefferson was still in office. And according to Reall, it won’t take place again until 2245. It won’t happen again for these two broods until our great-great-great grandchildren will be around.

Not a ‘cicada Armageddon,’ after all

Unlike annual cicadas—the flying bugs we see pop up every summer—periodical cicadas only emerge en masse on a recurring 13 or 17-year cycle. Most species tend to have black bodies, red eyes, and red-orange wing veins—a distinct coloring not found on larger and greener ‘dog day’ annual cicadas.

Geography also sets these insects apart. Periodical cicadas can only be found in North America, while annual cicadas can be spotted worldwide. This year’s dual event will feature Brood XIII—which emerges every 17 years in the Midwest, and includes sections of Illinois, Indiana, Iowa and Wisconsin—and Brood XIX.

The largest geographic distribution of all periodical cicada broods, Brood XIX emerges every 13 years also in Iowa, Illinois and Indiana, as well as in the Southeast, in slivers of Alabama, Arkansas, Georgia, Kentucky, Louisiana, Missouri, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Virginia, and Maryland.

For those living in any of the states that may bear witness to the double broods, the first sign that the cicadas are coming will be holes popping up in lawns, around trees and in the woods.

As we start hitting some of those warmer temperatures, we’re going to have nymphal cicadas emerging from those holes…they will be crawling up out of the ground in just absolutely stunning numbers. Adult cicadas typically only live for four to six weeks. And we’ll experience just an incredibly loud humming, buzzing noise from their singing, before they mate and then die.

Whether it will end up being billions or even trillions of cicadas emerging in totality is unclear, she noted. “Estimating cicada population sizes is difficult and scientists don’t have a great sense of the exact numbers. But that still doesn’t mean people in cicada hotspots will suddenly see double the amount of the flying bugs in their yards. There’s only one point of possible overlap at the edge of the ranges of both Brood XIII and Brood XIX in central Illinois, where cicadas aren’t typically as dense as they are in the middle of their ranges.

The area of overlap is likely to be very, very narrow, maybe just a few miles. I think a lot of people think it’s going to be ‘cicada Armageddon,’ with twice as many,” added Kritsky, who has studied the bugs for fifty years and created a citizen-science app that helps track their distribution. “I’m not expecting that.”

Are cicadas bad for the environment?

When mass amounts of cicadas pour out of the ground all at once, there are inevitable ecological effects. Events like these “cause major disruptions in the ecosystem. We call it a ‘cascade.’ Where you have this avalanche, this small change that then builds and builds and crashes through the ecosystem.”

Periodical cicadas are a desirable food source for a medley of animals—a list that includes birds, squirrels, and several household pets. A 2023 study led by Getman-Pickering found that during mass brood events, insect-eating birds consume fewer leaf-eating caterpillars, which allows the caterpillars to feast more heavily on the leaves of oak saplings, a process that can temporarily damage the entire tree.

Although large populations of cicadas are not considered ecologically destructive, young trees can also be weakened by the egg-laying process of mating cicadas, which can kill a sapling’s branches.

At the same time, the broods help move nutrients around an ecosystem and aerate soils, among other boons.

Plight of the buzzing bugs

Meanwhile, habitat loss driven by urbanization is a threat to cicada populations. If anything is covering the ground, if there’s cement, or if things have covered where their natural habitat is, [periodical cicadas] will not be able to move up through that.

Urban development forces the cicadas in an area to all converge on fewer remaining trees; which also heightens the spread of diseases, like sexually-transmitted fungal pathogens that cause infertility.

Climate change could also negatively influence the upcoming event. Warming temperatures are “certainly” causing the broods of periodical cicadas to come out earlier in the spring, according to Kritsky. A smattering of confused cicadas belonging to Brood XIII and Brood XIX were spotted in the springs of 2020 and 2023, having emerged off-cycle.

What climate change is doing is causing cicadas to come out actually earlier in May than they did a century ago.

Still, what scientists know about the climate impact on synchronized cicada emergences is limited because data is limited, according to Getman-Pickering. Rising temperatures and extreme weather events could, however, end up altering when broods come aboveground to mate, which reduces the survival chances of those populations as a whole, as safety in numbers is part of a brood’s survival strategy.

We’re potentially going to have more cicadas that are stragglers, and stragglers are much more likely to die and get eaten.

Cicadas on the menu

Meanwhile, a handful of daring Americans plan to sauté some of this year’s double brood. A professor of anthropology at Montclair State University and Nat Geo Explorer who researches edible insects, Cortni Borgerson will be harvesting cicadas during the phenomena, with the sole purpose of cooking them.

She compares the taste of a cicada to a sunflower or macadamia nut “with a pork-like flavor,” and the texture of a peeled shrimp. “A lot of times, insects are eaten as an additive, or powder, or something that’s really dry. Whereas these guys you could treat just like anything else,” Borgerson said. “Like something that you might be cooking up for a taco.”

Cicadas are edible, according to the University of Illinois Extension website. People eat them alongside other bugs—such as silkworms, locusts and crickets—worldwide. Past periodical brood events have inspired restaurants and eateries across the U.S. to incorporate cicadas into everything from ice-cream flavors to pizza toppings.

But just like with any other meat, Borgerson warns that when it comes to food safety, preparation is key. The anthropologist also cautions anyone interested in trying to catch and cook cicadas of their own to collect the insects from historically uncontaminated environments. Heavy metals or harmful chemicals may have polluted the soils they emerge from.

“I always tell people: ‘If you would garden in that space, you can harvest insects in that space,’” she said.

Not a fan of cicadas in the kitchen, Kritsky prefers to simply bear witness to the swarms visible during emergence events.

Come May, the Ohio-based scientist will be travelling to Illinois so he can see firsthand the throngs of bugs clumsily flitting aboveground after years below the surface. “It’s like having a David Attenborough special in your backyard,” said Kritsky.