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
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
The human brain doesn't stop developing until about 25 years old.
102
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217