Yawns are more contagious among people with closer relationships.
163
The human body contains over a billion miles of DNA.
147
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your body is creating and killing about 2.4 million red blood cells per second.
17
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Enamel is hardest substance in the human body.
61
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217