Yawns are more contagious among people with closer relationships.
163
Enamel is hardest substance in the human body.
61
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
When you take a step, you are using up to 200 muscles.
886
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
If your DNA was stretched out it would reach to the moon 6,000 times.
256