The life cycle of a cicada is interesting. According to Cicada Mania, the eggs are laid on trees that eventually fall and burrow in the ground. They live and thrive underground for 2-17 YEARS (!) until emerging as nymphs. The nymphs shed their outer layer and as they mature develop wings, fly, find a mate, and lay eggs in trees.
The noise outside in the summer is deafening at times, from the call of the males, and the response of the females. You can listen to one type here.