Billions Of Cicadas Are Starting To Pop Up Across The US After A 17-Year Snooze


Katy Evans

Katy is Managing Editor at IFLScience where she oversees editorial content from News articles to Features, and even occasionally writes some.

Managing Editor


Hi, friend. Image credit: Elliotte Rusty Harold/ 

Many of us wished we could have sat out 2020 but billions of cicadas in the US have got us beat having spent the last 17 years biding their time underground, waiting for the perfect moment to pop up, sprout wings, mate, and then die. Is it worth it? They presumably think so.

This is one of nature’s more curious lifecycles. Periodical cicadas in the North American genus Magicicada live underground for either 13 or 17 years, depending on which type they are, living off sugary sap from tree roots before collectively emerging in springtime in incredible numbers to shed their exoskeletons, stretch their wings and procreate. Theirs is a weird life, but they go out with a bang.


Cicadas that emerge at the same time are called Broods. Over the next few weeks, Brood X, born in 2004, will be impossible to miss, as large parts of the eastern US will vibrate to the sound of billions, even trillions, of cicadas getting it on after a 17-year wait.

To put it into perspective, when these cicadas first ventured underground Friends was still on TV and Mark Zuckerberg launched a little-known social network from his Harvard dorm room.


How the cicadas know when the 17-year cycle is up is a mystery to scientists, but we’re slightly more prepared for them now than the early European settlers who thought they were being visited by some kind of biblical plague. It’s thought the evolutionary strategy is safety in numbers. Predators like birds and small mammals can feast like kings and barely make a dent in their numbers.

Parts of the US are already seeing Brood X emerge, sharing photos and videos on social media, though it seems the emergences are localized with unseasonably cold weather meaning some of the bugs are waiting for a bit more warmth before they emerge to party in the Sun.


According to the National Weather Service, temperatures in the eastern US are currently about 10 degrees below normal, which could delay the swarms. The soil needs to be around 18°C (64°F) for them to emerge. Warm rain can also trigger their appearance.

Next week, however, temperatures are expected to rise and with them the hordes of cicadas. Brood X is expected to pop up in Maryland, Indiana, Delaware, Ohio, Pennsylvania, Tennesse, and Washington DC, according to the US Forest Service

Brood X cicada map
Active periodical cicada broods in the US. Brood X is in yellow. Image courtesy of: US Forest Service

The Washington Post's cicada forecast has the "peak bloom" between May 18 and 20. It's unlikely you'll miss them though. The males use drum-like structures on their abdomen to create a loud, high-pitched buzz that sounds similar to an electric rotor, while the females respond by clicking their wings together. This love song can exceed 90 decibels, about as loud as a motorcycle or lawnmower.


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