Noisy cicadas come back to life after years underground

Brood II cicadas will begin to appear on the East Coast in the next few weeks.

(CBS News) If you live on the East Coast, fair warning, you're about to be invaded, but it's not the zombie apocalypse. It's actually an invasion by billions of creatures coming back to life after being buried since the 1990s.

In one of nature's great mysteries, the Brood II cicadas are expected to appear en masse along the East Coast this spring, which is a ritual nearly two decades in the making.

The bugs will make their presence known with a buzzing racket that's been compared to the sound of a New York subway train.

"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."

These insects spend nearly their entire lives underground, feeding off the roots of trees. They go through five stages before reappearing above ground from New England to North Carolina.

"What will happen is the nymphs will come up and they will shed their nymphal skin and they'll crawl up into the trees and they'll take about five days to harden and then they'll start for next four to six weeks calling and looking for mates," said Gibbs.

This year the invasion is forecast sometime between mid-April and late May, at which point residents will be bombarded with millions of cicadas per square mile.

The exact time is unknown, as Gibbs explains that the ground has to be 64 degrees before they appear.

A big positive about these bugs is that they're harmless to both trees and humans, and are only a nuisance because of the sound they make.

Cicadas: the familiar sound of summer

"It'll be noisy. There's no getting around the noise," said Gibbs. "And again that's just the males looking for females. What's noisy to a human is the sound of love to another cicada"

If this particular love song is not music to your ears, after about a month the cicadas will disappear again until 2030.