Yawns are more contagious among people with closer relationships.
163
Enamel is hardest substance in the human body.
61
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
If your DNA was stretched out it would reach to the moon 6,000 times.
256
One human hair can support 3 ounces.
191