Why Insects Rule Earth But Can't Conquer the Sea

Insects dominate Earth with over a million known species, but their success comes with strange limits. This animated explainer unpacks why they stay small, why their breathing and exoskeletons stop them from becoming giants, and how ancient oxygen once made bigger insects possible. Then we dive into two bigger mysteries: why insects never truly returned to the ocean, and why artificial lights make them spiral, flip, and crash. The answers reveal how evolution, physics, and tiny body plans shaped the most diverse animals on the planet. Subscribe for more animated science explainers. Tags: insects, insect evolution, animal diversity, evolutionary biology, why insects are small, giant insects, exoskeleton, tracheal breathing, insects in ocean, marine insects, phototaxis, dorsal light response, science explained, animated explainer, entomology