The focusing muscles of the eyes move around 100,000 times a day. To give your leg muscles the same workout, you would need to walk 80km (50 miles) every day.
21
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
The average person in their lifetime will spend an estimated 20,160 minutes kissing!
212
In 2011, archaeologists discovered the skeletal remains of a Roman couple who have been holding hands for 1,500 years.
81
Only about 2% of the world population has green eyes.
36