.STRUCTURE IS Curing Americans to all type of eyeglasses. On April 8th millions watched a complete sun eclipse. Numerous will be much less charmed when, in the coming days, mountains of cicadas seem in the nation's Midwest and also south-east. The swarm will definitely be actually unusually sizable considering that 2 sorts of the bug-- Family XIII and Brood XIX-- are actually arising all at once. The last time they showed up simultaneously resided in 1803, when Thomas Jefferson was head of state. Why perform the cicadas possess such an unique life cycle?