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
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
The human brain doesn't stop developing until about 25 years old.
102
If you hold farts in during the day, they'll just come out when you sleep.
16
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
In 30 minutes, the average body gives off enough heat (combined) to bring a half gallon of water to boil.
198