The smallest bone lives in your ear

In the middle ear, hidden behind the eardrum, live the three smallest bones in the body: the hammer, the anvil and the stirrup. They form a tiny chain named after a blacksmith's shop.

The stirrup is the champion of small: it measures about three millimetres, less than a grain of rice, and weighs just a few milligrams. Its job is huge for its size. When the eardrum vibrates with a sound, this chain of little bones picks up the tremor and pushes it toward the inner ear, amplifying it on the way.

Without that push, the vibrations in the air would fade as they hit the fluid of the inner ear, and you'd barely hear a thing.

Next time a song gives you goosebumps, remember: all of it passed through a bone the size of a crumb.