The average sperm cell swims at 8 inches per hour.
76
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Enamel is hardest substance in the human body.
61
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46