2 cicada broods are popping up together for the first time in 221 years — and they'll meet in Illinois

• Two broods of periodical cicadas are emerging simultaneously for the first time in 221 years.
• Broods XIII and XIX overlap in a small portion of Illinois, around Chicago.
• People can help scientists keep track of these insects using citizen science apps.

2024 is the year of the cicadapocalypse.

That's because two broods of periodical cicadas — Broods XIII and XIX — will emerge from their underground lairs simultaneously for the first time in 221 years.