Yawns are more contagious among people with closer relationships.
163
The human brain doesn't stop developing until about 25 years old.
102
Enamel is hardest substance in the human body.
61
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
The human body contains over a billion miles of DNA.
147
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