Smashing mantis shrimp. Snapping trap-jaw ants. Stinging jellyfish. Some of the fastest living things — at least over short distances — are also the smallest. A new mathematical model explores how the smallest and speediest things on Earth generate their powerful jumps, snaps, strikes and punches. The model could help explain why robots can’t hold a candle to the fastest-moving insects and other tiny-but-powerful creatures, and how they could get closer.