We usually think of spiders sensing the physical vibrations of prey on their webs. But researchers believe spiders also use their webs to extend their hearing. Using a soundproof room, researchers found that orb-weaving spiders use their webs not just to capture insects but to capture sounds, which may give them a leg up on incoming prey and predators. Writing in the Proceedings of the National Academy of Sciences, researchers found that spider silk was so sensitive it could detect the movement of air particles vibrating from soundwaves. Spiders detect these tiny movements through sensory organs at the tips of their legs. That makes their spider webs something like a giant acoustic antenna up to 10,000 times larger than the spider itself.