Ballistic high powered spider webs overcome dangerous prey defenses

Spiders exhibit a remarkable range of silk-based predatory tactics, but usually avoid capturing ants since they are highly defended. Here we report on a spider that exclusively hunts aggressive Oecophylla ants by isolating and immobilising individual workers using a extraordinary ballistic snare that lures ants, then propels them into its core web at extreme speed. By serial arrangements of tension lines, small pre-strains of the silk are sufficient to reach power densities of up to two megawatts per kilogram actuator mass, which surpasses the performance of other natural spring-actuated systems. Thus, the ultimate prey specialisation in these spiders has led to the evolution of extreme web performance.