Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
The average sperm cell swims at 8 inches per hour.
76
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
When you take a step, you are using up to 200 muscles.
886
The human brain uses approximately as much energy as a 10 watt light bulb.
120
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22