It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Obsessive nose picking is called Rhinotillexomania.
101
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
All 13 minerals necessary for human life can be found in alcohol beverages.
282
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Tigers can see 6 times better at night than humans.
305
Every human spent about half an hour as a single cell.
144