Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
When you take a step, you are using up to 200 muscles.
886
The average sperm cell swims at 8 inches per hour.
76
Enamel is hardest substance in the human body.
61
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13