Yawns are more contagious among people with closer relationships.
163
By weight, Bone is five times stronger than steel.
417
The human brain is more active during sleep than during the day.
28
In ancient Egypt, priests plucked EVERY hair from their bodies, including their eyebrows and eyelashes.
130
Having sex can make a woman look younger and more attractive due to the release of estrogen and collagen.
346
If Earth's life was compressed into 1 year, then humans would have been around for only 2 seconds.
15
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
If the human eye was a digital camera, it would have 576 megapixels.
25