It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
The average sperm cell swims at 8 inches per hour.
76
Enamel is hardest substance in the human body.
61
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149