A cicada is a large insect famous for its loud buzzing or clicking song, which only the males produce. If you've ever heard a deafening chorus of buzzing on a hot summer day, you were probably hearing cicadas calling from the trees. They make this sound using special organs on their abdomen called tymbals, which vibrate like tiny drums. The noise can be as loud as a lawnmower.

Cicadas have one of the strangest life cycles in nature. After hatching, young cicadas burrow underground and spend years (sometimes 13 or 17 years!) feeding on tree root juices in the dark. Then, seemingly all at once, millions emerge from the soil, climb up trees, shed their shells, and spend a few weeks flying, singing, and mating before they die. The empty brown shells they leave clinging to tree bark are a familiar sight in summer.

These periodic emergences create spectacular natural events. In some years, called brood years, billions of cicadas appear simultaneously across entire regions, covering trees and filling the air with their collective song. Scientists still study how cicadas coordinate these mass emergences so precisely after spending so many years underground.