As of August 2016, the United Nations Department of Economic and Social Affairs' Population Division estimated the world population at approximately 7.4 billion
The three smallest bones in your body are all found inside your ear, and you would be completely deaf without them.
Known formally as the malleus, incus and stapes (and informally as the hammer, anvil and stirrup, after their approximate shapes), all three of these tiny bones could fit easily on a penny at the same time.