.TYPE IS Attending To Americans to all sort of eyeglasses. On April 8th millions saw an overall photovoltaic eclipse. Lots of will certainly be actually less mesmerized when, in the coming times, mountains of cicadas seem in the nation's Midwest and also south-east. The throng will certainly be actually unusually big because two forms of the insect-- Brood XIII and Family XIX-- are emerging at the same time. The last time they appeared all at once was in 1803, when Thomas Jefferson was head of state. Why do the cicadas have such an unusual life cycle?