.NATURE IS TREATING Americans to all kinds of eyeglasses. On April 8th thousands experienced an overall photovoltaic eclipse. Lots of are going to be less mesmerized when, in the coming times, mountains of cicadas seem in the nation's Midwest as well as south-east. The flock will certainly be actually abnormally sizable because two types of the bug-- Family XIII and also Brood XIX-- are developing simultaneously. The last time they seemed concurrently resided in 1803, when Thomas Jefferson was president. Why carry out the cicadas have such an unique life cycle?