Here's a close look at the 17-year cicadas.
Once every 17 years, like clockwork, an event takes place through a portion of the eastern U.S.--the emergence of the Brood X periodical cicada. This curious creature lives underground for 17 years, harmlessly sipping the sap from tree roots, emerging only when its biological alarm clock goes off and soil temperatures hit 64 degrees.
The emerging cicadas start out with white bodies, roughly two-inches long, and at this point they're especially vulnerable to predators. But within two or three hours their shells begin to darken and their wings unfold and dry, thereby enabling them to take to the air.
That same night, they climb the nearest vertical surface and when the time is right, they shed their skins, signaling their transformation into adulthood.
And ultimately, in what is considered the world's largest insect swarm, the cicadas march off into droves in search of trees--and the perfect mate. While there, the males produce their mating cry--a deafening shrill that can be heard up to a mile away.
Despite their numbers, which scientists can estimate as being in the billions, cicadas are perfectly harmless creatures. They don't sting or bite, they aren't poisonous and they do very little damage to plants.
Owing to their numbers, however, they can certainly put a damper on a picnic or outdoor wedding. And their crunchy shells, which litter sidewalks and yards, are a bit smelly. Cicadas are a food source for wildlife, including birds, snakes, spiders and squirrels.
In her final dying act, the female cicada lays 400 to 600 eggs in a tree branch, and six to 10 weeks later, the eggs hatch and the nymphs fall to the ground, where they tunnel to a depth of about 12 inches and begin setting the stage for the next cicada emergence precisely 17 years later.
But in the interim--roughly five weeks--the cicadas go about their business, buzzing in the treetops and reproducing before their final, noisy farewell.