436. The emotions are mostly associated with fear is interest. Some psychologists have gone so far as to suggest that fear has two invisible faces: one, the wish to flee and, second, the wish to investigate.

437. Sleep is an good indicator of recovery . It is linked with fatigue , memory and concentration .The better you sleep , the better the days are going to avoid depression but in limited manner not to much or not to less.

438. Bullfrogs and dolphines are some animals that barely sleeps or don't required sleep.

439. Humans are the only mammals that can willingly delay sleep.

440. People who don’t get enough sleep are more likely to have bigger appetites due to the fact that their leptin levels (leptin is an appetite-regulating hormone) fall, promoting appetite increase.