Yawns are more contagious among people with closer relationships.
163
The average sperm cell swims at 8 inches per hour.
76
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
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
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
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