Illinois is hit with cicada chaos. This is what it's like to see, hear and feel billions of bugs (2024)

RIVERWOODS, Ill. — The ground seemed to undulate at night, alive with bugs. Crawling cicada nymphs, striving to get higher after 17 years underground, marched en masse toward and up trees, pausing to shed their skin and emerge as adults. And then the fun began.

Cicada chaos is flourishing and flying. Trillions of once-hidden baby bugs are in the air, on the trees and perching upon people's shirts, hats and even faces. They're red-eyed, loud and frisky.

"What you saw was biblical," said biologist Gene Kritsky, who has been chasing periodical cicadas for 50 years, yet was still amazed by the 3 to 5 million cicadas crowding a small patch of Ryerson Conservation Area north of Chicago. "There are things I've seen this time that I've never seen before."

It's an only-in-the-United-States spectacle, the last of the triple crown of rare forecast natural wonders.

First, there was April's solar eclipse, followed by May's Northern Lights unusually far south. Now the great dual periodical cicada emergence of 2024 — an event of a magnitude not seen since 1803 — has burst from below to join the earlier shows in the sky.

It's lasting weeks longer than the other two fleeting natural rarities, but in many places the cicada invasion is starting to wind down.

The males are singing for sex and won't stop until they get a female cicada's flapping wing consent. There were places in Illinois the decibel level hit 101, louder than a lawnmower, flowing in waves as an ever-present buzzing drone that seems like aliens descending in a science fiction movie.

The sound abounds in the suburbs of Chicago, such as Oak Brook, but has already faded farther south in the state, including where two broods overlap. In an asphalt-laden DuPage County shopping plaza, cicadas mobbing the branches of the only tree drowned out the next door automated car wash's whirring hoses and spinning brushes.

David Quinn, visiting the Chicago area from Northern Ireland, said, "whenever we were driving, we were thinking there was something wrong with the car. All that noise. It's the bugs."

Buggy tourism

Cicada chasers in 18 Midwestern and Southern states have submitted photos of the bugs to the Cicada Safari app, mostly concentrated in two areas, each an emergence of different broods.

The Northern Illinois brood, called XIII and coming out every 17 years, is extra dense, with as many as 1.5 million bugs per tree-covered acre — nearly a billion per square mile — in some places like Ryerson, Kritsky said. The Great Southern Brood, which arrives every 13 years, stretches from Virginia to Missouri and southern Illinois to Georgia.

In Central Illinois, especially around Springfield, the two broods just about overlap. But it's hard to tell which brood a cicada belongs to.

At the Lincoln Memorial Garden in Springfield, Executive Director Joel Horwedel figured he'd put up a pushpin map of the United States to track where visitors came from. He wasn't thinking big enough. At the bottom of the map under a scrawl of "Out of USA" are "Japan Belgium Lithuania Germany England Japan (Kyoto)."

"It has been truly incredible how many people we're getting," Horwedel said.

U.S. Department of Agriculture research entomologist Rebecca Schmidt said usually when she gets calls about bugs, it's something bad and scary, like murder hornets. Periodical cicadas are different and "people are coming to us for good reasons, like 'tell us more, we're very excited, enthusiastic about this,'" she said.

"It's a nice little gateway to these amazing things that the natural world does, some of which we can predict with a lot of accuracy," Schmidt said.

Wearing a T-shirt that says "I survived the cicada invasion and all I got was this shirt (and some earplugs)" that she won for posing a cicada on a toy skateboard, retiree Cindy Harris of Springfield walked through the Lincoln Garden pointing out cicadas.

"I don't know why I'm fascinated by them," Harris said.

Cicada fascination

Jennifer Rydzewski, an insect ecologist at DuPage County Forest Preserve, donned a cicada hoody costume — complete with bulging red eyes made by a 3D printer — that she wore in an educational social media post and joined a cicada walking tour.

For her video bug gig, she studied how the bugs move.

"You'd go outside and the sidewalks are just covered in them, all of them marching in the night," she said of the still wingless nymphs.

"They're very hunchbacked, just kind of slowly, almost alien-like to me, crawling with all their little appendages," Rydzewski said. But she adds, "they look really cute."

The only possible danger is to young trees, mostly from when the females slit notches in branches to lay their eggs, Rydzewski said. So many newly planted trees sport white protective netting — a contrast to the black winged bugs lined up on some adult trees.

Overall, cicadas play an important role in the local ecosystem as fertilizer, aerating the soil and food for birds and other animals, said Marvin Lo, a tree root biologist at the Morton Arboretum.

The arboretum was full of cicadas, cicada-peepers and scientists looking at the bugs. The critters didn't disappoint. They were there in force and weirdness. The Associated Press found a blue-eyed cicada — a one-in-a-million find.