Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Yawns are more contagious among people with closer relationships.
163
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
One human hair can support 3 ounces.
191
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
Enamel is hardest substance in the human body.
61
The average person's skin weighs twice as much as their brain.
131