Spiders leg slit sensors for vibrations now made into an electronic sensor:-http://www.livescience.com/49083-spider-inspired-vibration-sensor.html?cmpid=558757-"Spiders have an organ called the "slit sensilla" near their leg joints that detects tiny vibrations in their environment. By mimicking the design of this organ, researchers produced a sensor that is extremely sensitive and flexible, and could be used in wearable electronics.-"The slit sensilla in spiders consists of parallel slits of different lengths embedded in their exoskeleton, resembling the strings of a harp, which senses movement by opening and closing in response to forces exerted on it. The slits are connected to nerves that relay information about the vibrations to the spiders' brains."