Yawns are more contagious among people with closer relationships.
163
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
The average person's skin weighs twice as much as their brain.
131
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59