A bug the size of a small crocodile? Or as large as a basketball player? As scary as it seems, supersized, insect-like creatures such as these roamed Earth long before humans. This peek into prehistory introduces seven of these fascinating megabugs - the ancestors of modern-day insects, spiders, crabs and other arthropods - which lived from 480 million to 47 million years ago. It explores when, where and how they each lived, why they grew so big and what caused their eventual extinction.