1. The brain is more active at night than during the day. Scientists don't know yet why this is.
2. The higher your IQ, the more you supposedly dream.
3. Facial hair grows faster than any other hair on the body.
4. The nail on the middle finger grows faster than the other fingernails.
5. Fingernails grow nearly four times faster than toenails.
6. The lifespan of a human hair is 3 to 7 years on average.
7. The acid in your stomach is strong enough to dissolve zinc. It doesn't destroy the stomach because the stomach walls constantly renews itself.
8. Women's hearts beat faster than men's.
9. Women blink twice as many times as men do.
10. Women are born better smellers than men and remain better smellers over life.
11. Men burn fat faster than women by a rate of about 50 calories a day.
12. Men get hiccups more often than women.
13. A man has approximately 6.8 liters of blood in the body while women have approximately 5 liters.
14. The largest cell in the body is the female egg and the smallest is the male sperm.
15. During your lifetime, you will produce enough saliva to fill two swimming pools.
16. Babies are born with blue eyes more than any other color. The melanin in their eyes needs time to be fully deposited or to be darkened by ultraviolet light to reveal the baby's true eye color.
17. Men have erections every hour to hour and a half during sleep. This is because the combination of blood circulation and testosterone production can cause erections during sleep and are a necessary part of REM sleep.
18. After eating too much, your hearing is less sharp.
19. If your saliva cannot dissolve or mix with food, you will not be able to taste that food (try tasting something after drying off your tongue)
20. Noise causes the pupils of your eyes to dilate. Even very small noises can do this.