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. Their orphan progeny will then return to the ground and live the next 17 years in silence.

Over the next several weeks, billions of mid-Atlantic cicadas will hear the call of spring and emerge from their cozy bunkers. This year’s group, born in 2004, is known as Brood X. They’ll start their journey to the surface when soil temperatures reach around 64 degrees Fahrenheit.

While they’ll emerge in biblical numbers, they’ll be blanketing only a small slice of the country.

Cicadas appear every year on the East Coast, but it’s a different 17-year crew that wakes up each time. (There are some 13-year broods of cicadas in the Southeast, too.) Emerging in these humongous annual batches is likely an evolutionary strategy. There are so many cicadas all at once, predators (such as birds and small mammals) can’t make a meaningful dent in their numbers.

In sum, the broods lay claim to much of the eastern United States, stretching from New England to Oklahoma. You can see all of the US broods on the US Forest Service map below.

Brood X (shown in yellow) will be seen in Maryland, Delaware, Pennsylvania, Indiana, Ohio, and eastern Tennessee.

And while their mating calls are loud and annoying, cicadas are one of nature’s beautiful mysteries: No one — not even Sir David Attenborough — knows how the cicadas are able to count to 17 years underground.

Click play on the video below to watch Attenborough seduce a male cicada by imitating the clicks a female makes. Enjoy!