.STRUCTURE IS TREATING Americans to all type of eyeglasses. On April 8th millions watched an overall solar eclipse. Several are going to be actually less knocked out when, in the coming days, trillions of cicadas appear in the nation's Midwest and south-east. The flock is going to be actually extraordinarily huge due to the fact that two types of the insect-- Brood XIII as well as Brood XIX-- are actually arising simultaneously. The last opportunity they showed up together was in 1803, when Thomas Jefferson was head of state. Why carry out the cicadas possess such an unusual life cycle?