.TYPE IS Caring For Americans to all sort of eyeglasses. On April 8th millions saw a complete solar eclipse. Numerous are going to be actually less mesmerized when, in the coming times, mountains of cicadas seem in the country's Midwest and south-east. The throng is going to be extraordinarily sizable because two types of the insect-- Brood XIII as well as Brood XIX-- are actually developing simultaneously. The final time they seemed simultaneously was in 1803, when Thomas Jefferson was head of state. Why carry out the cicadas have such an unique life cycle?