It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
There's 100 trillion good bacteria living in your body.
17
You see your nose at all times, your brain just chooses to ignore it.
30
All humans have the ability to see ultraviolet light, but it is passively filtered out by the eye's lens. People who undergo surgery to remove the lens can detect ultraviolet light.
22
In one day, adult lungs move about 10,000 litres of air.
11
You can hear the blood flowing through your ears if you find a quiet place and cover them tightly.
19
