GREEN LANE, Pa. - Brood X Cicadas are slowly beginning to join us here above ground.

"Probably within the last week or so they've started popping out," said Amy Korman, a horticulture extension educator at Penn State.

It's caused some excitement for a homeowner in Green Lane. She saw one red-eyed little guy on her deck.

We found dozens of his friends and family members chilling on a tree in her yard.

"When the temperature of the ground at about 8 inches below the soil surface reaches 64-ish degrees and it stays that warm that's one of their environmental cues that says hey it's time to get out of here," Korman said.

They'll hang out and create some buzz for about a month in their adult stage, mate and then fly off to Cicada heaven, while their babies hatch, burrow back underground and repeat the process for another 17 years.

"But there's so many of them that plenty enough will meet and then produce the next generation but it takes 17 years for this particular species to grow from an egg to an adult," Korman said.

This'll be happening all up and down the east coast, in 15 states. And there's no need to fret - they're harmless.

Korman says sit back and appreciate the science.

"It's a very unusual phenomenon. We should just enjoy it," Korman said.

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