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
The average sperm cell swims at 8 inches per hour.
76
Fingers prune underwater not because of them absorbing the water or washing away the oil, but because of an evolutionary trait caused by the brain to enhance the grip of your fingers underwater.
24
The human brain uses approximately as much energy as a 10 watt light bulb.
120
There are about 1,400 different species of bacteria in your belly button.
10
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
You can hear the blood flowing through your ears if you find a quiet place and cover them tightly.
19