Around mid-April, in an event that happens only once every 17 years, billions of cicadas will crawl out of the ground and mate. This 17-year cicada brood is known as Brood II, which lives along the east coast from North Carolina to Connecticut.
The exact time is unknown, but when the ground warms to 64 degrees, sometime between mid-April and late May, residents will be hit with millions of cicadas per square mile, reports CBS News. The males will make their distinctive noise to call for mates, and in a swarm it can sound like a subway train.
The females will lay 400-600 eggs in the ends of twigs, and both adults will die shortly after mating. In the summer, the eggs will hatch and their offspring will burrow into the ground to feed on roots until it's their turn to mate — in 17 years.
"Brood II is a periodic cicada that hatches out every 17 years," said Craig Gibbs, an entomologist at the Wildlife Conservation Society's Queens Zoo. "The specific thing about these 17-year cicadas is they are going to be a very dark colored body. They have really bright red eyes, and they also have bright red wing veins."
The cicadas are harmless to trees and humans. They don't bite, but they do make a lot of noise. After four to six weeks the noise will be gone, and Brood II won't be back until 2030.