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
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human body contains over a billion miles of DNA.
147
The average sperm cell swims at 8 inches per hour.
76
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217