For 17 years, cicadas do very little. They hang out in the ground, sucking sugar out of tree roots. Then, following this absurdly long hibernation, they emerge from the ground, sprout wings, make a ton of noise, have sex, and die within a few weeks. Then, their orphan progeny return to the ground and live the next 17 years in silence. Rarer are the 13-year cicadas, which do the same, but in a little more of a hurry — spending just 13 years underground.

Cicadas appear most years on the East Coast of the United States — sometimes ahead of schedule — but it’s a different 17- or 13-year crew that wakes up each time. (There are also, separately, some annual cicadas that emerge every year.)

This year, though, will be a rare event. Two groups — known as “broods” — are waking up during the same season. There will likely be billions, if not trillions, of the insects. According to NPR, the last time these two broods emerged […]