Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
The human brain doesn't stop developing until about 25 years old.
102
Your thumb is about the same size as your nose.
124
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59