It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
Yawns are more contagious among people with closer relationships.
163
Poor eyesight (myopia) is associated with higher IQ.
232
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
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 doesn't stop developing until about 25 years old.
102
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18