By Molly Daly

PHILADELPHIA (CBS) – Once the weather and the ground warm up, some parts of the Delaware Valley will see one of nature’s spectacles — the mass emergence of a mess of periodical cicadas that have taken 17 years to mature.

Despite what you may have heard about hordes of the red-eyed insects engulfing the area like some kind of biblical plague, Academy of Natural Sciences Curatorial Assistant Greg Cowper says it looks as if the Magicicada swarms will be localized — and a lot depends on what’s happened since their parents saw sunlight:

“What kind of human disturbances happened in the seventeen years since 1996. If more streets were paved and more buildings were built, all those areas will be disturbed where they traditionally emerged, they may not be able to again.”

But if they do, Cowper says it’s nothing to worry about.

“I know there’s a lot of cicadas, but really, they do no damage to the trees, they’re not poisonous, they don’t carry disease, they don’t bite, they don’t sting. It’s really a neat natural phenomenon, and it’s neat to just kick back and enjoy the show.”

And they only live a couple of weeks — enough time to mate and start a new 17-year cycle.