They've been hiding under your feet since 1999, but they'll soon emerge by the billions. While the rumbling of their mating calls may scare you, imagine their surprise to learn how the world has changed since they were last seen 17 years ago. Donald Trump is a presidential frontrunner -- along with First Lady Hillary Clinton -- and the current president is black. But they should be relieved to learn that the Y2K scare, which was the big fear when they last said goodbye, was a bust.

They're circadas who come out like clockwork in several eastern U.S. states every 17 years as the ground warms up to 64 degrees, usually in May. Soon, their numbers will swell into the billions in Ohio, New York, Pennsylvania, Maryland, Virginia, and West Virginia.

But this is fortuntely is not like a biblical locust plague. Unlike the locusts, cicadas can't chew. They don't destroy plants, trees, and other vegetation. Instead, if they can keep from being eaten for long enough, they will eventually drink tree sap, which doesn't have any overreaching negative effect on the environment.

While the circada class of 2016 is on a 17-year life cycle, another follows a 13-year span. Their lives started underground and stay there until their last weeks when they emerge to reproduce. That unmistakable rumble you hear are the males desperately seeking mates. They have no Tinder apps for that. Cicada Mania reports that this current 17-year cycle, which began in 1999, begins to end next month.

Some people have a taste for the pests!

Lead Stories' Trendolizer™ is constantly scouring the web for the hottest news, viral videos and images.