In the damp, warming soils of the American Midwest, an ancient, subterranean clockwork has just completed its silent countdown. For nearly two decades, billions of wingless nymphs have tunneled through the dark, sipping the watery sap of deciduous tree roots in absolute obscurity. Then, in a synchronized response to soil temperatures hitting a critical threshold of 64 degrees Fahrenheit, they breached the surface, transforming the quiet forest floors of Illinois, Indiana, and Missouri into a crawling, iridescent carpet of life. This spring marked a historic biological event: the simultaneous emergence of the 17-year Brood XIII and the 13-year Brood XIX. Not since 1803, during the presidency of Thomas Jefferson, have these two specific cohorts of periodical cicadas (genus Magicicada ) risen from the earth at the exact same moment. The resulting spectacle has provided entomologists with an unprecedented living laboratory to s...