大象传媒

In the forests of Madagascar, the aye-aye hunts for prey hidden deep inside wood. It's armed with one of nature's weirdest weapons, an extraordinary, thin, bony finger. When it comes to breaking and entering, this finger is the skeleton key. The aye-aye uses it to tap the wood - sounding out any hollow areas. It can tell if there's anything moving inside. In slow motion, another trick behind the aye-aye's tapping is revealed: After each tap, the fingernail is gently dragged along the surface. Scientists think the aye-aye is also picking up tiny vibrations. It is able to do this because its finger is so bony that it resonates. This allows it to fine tune its picture of what lies under the surface. The ears are huge and extremely mobile. They form a tent to capture sound, adding to the minute sensory input travelling through the finger. It's found something - a channel three centimetres below the surface. All its powers of surveillance now focus together. The eyes are shut, perhaps to heighten the other senses. When the grub hears the tapping it starts to move providing the aye-aye with yet more clues. It rips the wood apart. The aye-aye doesn't go straight for the grub, it's smart: it chisels in halfway up the channel, hoping to find even more prey in the neighbourhood. An acute sense of smell confirms the presence of a grub at the far end. To reach it, the finger will have to switch to a different function. The nail, which was earlier used for scraping, now becomes a hook. The grub's safe haven has been cracked, thanks to the aye-aye's all-purpose skeleton key.