Meet the spring harvestman (Rilaena triangularis), a species of arachnid in the harvestmen (Opiliones) order, widely distributed across Europe and parts of North America. Often called “daddy longlegs,” harvestmen aren’t actually true spiders; they sport a single fused body segment and a highly centralized nervous system. Lacking venom and silk, they don’t spin webs. Instead, they roam the night using their unusually long second pair of legs not for walking, but strictly as sensory “feelers” to probe their surroundings for small invertebrates, fungi, or decaying plant matter. But their coolest survival trick is a defensive self-amputate: if a predator grabs a leg, the harvestman can instantly discard the limb to escape. The detached leg will continue to twitch and squirm on its own for several minutes, completely distracting the attacker. It is a simple but brutally effective strategy—and it clearly works, as these fascinating creatures have remained virtually unchanged for over 400 million years!