Once cicadas emerge from the ground, they only live for a few weeks—just enough time to hopefully mate, before they die or become snacks for local predators. But they actually live for 17 years, nearly all of which is spent underground in the nymph stage. That makes the Brood II cicadas one of the longest-lived insects in the world. But it’s not the top. That would be the queen termite, which can live for decades.