.NATURE IS Caring For Americans to all kinds of spectacles. On April 8th thousands witnessed a total photovoltaic eclipse. Many will certainly be less mesmerized when, in the coming days, mountains of cicadas seem in the country's Midwest and south-east. The throng will be actually uncommonly sizable because pair of forms of the bug-- Brood XIII and Brood XIX-- are actually developing at the same time. The final opportunity they seemed at the same time was in 1803, when Thomas Jefferson was head of state. Why do the cicadas possess such an uncommon life cycle?