Billions of cicadas are expected to emerge this spring in an occurrence that has been described as “once in a lifetime” — and Illinois will be at the center of it.

The 2024 cicada explosion will see two different broods of cicadas – one that lives on a 13-year cycle and another on a 17-year cycle – emerging from underground at the same time.

The rare dual emergence hasn’t happened since 1803.

“While any given 13-year brood and 17-year brood can occasionally emerge at the same time, each specific pair will see their cycles aligned only once every 221 years,” NBC News reported. “What’s more, this year’s cicada groups, known as Brood XIII and Brood XIX, happened to make their homes adjacent to one another, with a narrow overlap in central Illinois.”

That means Illinois will be in a unique position for this unique occurrence.

For the Chicago area, Brood XIII will be most seen in parts of northern Illinois and Indiana, and possibly even in Wisconsin and Ohion, in late May 2024, Dr. Gene Kritsky, dean of Behavioral and Natural Sciences at Mount St. Joseph University in Cincinnati said in a 2023 press release.

According to an article from the University of Illinois Urbana-Champagne Extension, the Northern Illinois Brood’s emergence typically occurs in May and June, and lasts approximately four weeks. Although mostly harmless, the noise of the insects can be disruptive, the university said. Additionally, eggs from adult cicadas on twigs and shoots could cause “substantial damage” in newly planted orchards.

Wherever you may be in Illinois this summer, good luck with the noise. It might be time to invest in some earplugs.