In their prime: how trillions of cicadas pop up right on time
Right now, across much of the midwestern and eastern US, trillions of cicadas are crawling out from the soil. And this year is extra special, because two broods are erupting from the ground at once. The first brood hasn\u2019t been seen for 13 years, the other for 17 years and the last time they emerged together Thomas Jefferson was president. Ian Sample speaks to entomologist Dr Gene Kritsky to find out what\u2019s going on, why periodical cicadas emerge in cycles of prime numbers and how they keep time underground. Help support our independent journalism at theguardian.com/sciencepod