Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
In one day, adult lungs move about 10,000 litres of air.
11
It takes about 20 seconds for a red blood cell to circle the whole body.
102
If the human eye was a digital camera, it would have 576 megapixels.
25
When you kiss someone for the first time, you get a spike in the neurotransmitter dopamine, making you crave more.
23
Early American humans hunted car-size armadillos and used their shells for houses.
12
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Human hair and fingernails continue to grow after death.
7