Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
Your body is creating and killing about 2.4 million red blood cells per second.
17
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
It takes about 20 seconds for a red blood cell to circle the whole body.
102
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127