If you happen to be in the Onondaga Nation-Nedrow area, you may run into some unexpected guests -- Periodical cicadas.

They're swarming and humming all over the place. That's because they usually live underground, but make a rare appearance once every 17 years. At that time, they have matured and are ready to mate.

Researchers have flocked to the area to catch a glimpse of the huge insects.

"There are so many of them and they're hitting cars. I drove down there just to hear them because I'm not fortunate enough to live where they are emerging. But, I think I left with like five of them in my car just because you can't open the door without them getting in," said  Extension Entomologist Kim Adams.

Once the periodical cicadas emerge, they only live for a few weeks. 

During that time, the females will lay eggs that sink into the ground, beginning a new generation.