What are some interesting facts about humans?

Some interesting facts about humans are as follows:

1. Human skin has 1000 different species of bacteria on it.

2. The human child is born with 300 bones, and reach adulthood with 206 bones.

3. Human eyelashes last about 150 days.

4. A human heart beats about 100,000 times a day 

5. The highest blood flowing organ in humans is the kidneys.

6. Human lungs are the only organs in the body that float.

7. Humans can produce enough saliva to fill two bathtubs a year.

8. Humans blows air out of the nose at 100 miles per hour, while sneezing.

9. Humans are taller in the morning than at night.

10. Humans blood vessels can circle the globe.

11. An adult human has 2000-4000 taste buds.

12. Human body has more than 600 muscles.

13. Ear contains the smallest bone in the human body.

14. The human eyeballs are actually a part of the brain.

15. Human have between 2 and 5 million sweat glands.

16. Human bones are 4 times stronger than concrete.

17. Human fingernails grow four times as fast as their toenails.