Cicadas are winged insects, known for the songs sung by most, but not all, males of the species. They are better known for their swarming behavior which occurs every 13 to 17 years, depending on thee brood, or generation. Most of their lives are spent burrowed in the ground. Right before they reach adulthood they emerge, staying above ground only for a few weeks with the sole purpose of mating. There are 23 broods in North America, with the Cincinnati scheduled to see another visit from Brood X (a 17-year variety) in 2021.