SleEp and dReaM

      Sleep and dream

    Big animals sleep less and small animals sleep more. Elephants and giraffes sleep only 2 to 4 hours a day. Bats, opossums, and armadillos sleep 18 hours a day or more! Even kids need more sleep than grownups. A newborn baby sleeps 17 to 18 hours a day. A 10-year-old needs about 10 hours of sleep a night. Grownups need between six and nine hours of sleep a night. Some people need more sleep than others.  

           Why do we have to sleep?

Scientists do not know for sure why you sleep. They do have some ideas.

Safety could be one reason for sleep. People and other animals might sleep because it keeps them safe at night. It’s hard to see in the dark. Enemies could sneak up and attack animals that are wandering in the darkness. Most mammals and birds go to trees, underground dens, or nests at night. Prehistoric people went into caves or other shelters. They covered up with furs and fell asleep. You go into your home at night and snuggle up in bed.

Sleep might also help your body work better. Things go wrong if you do not get enough sleep. It is hard to think and work and play unless you get sleep. 

Why do we dream? 

Scientists have done many studies on dreams. They think your senses may have a lot to do with dreams. In dreams, you see and hear things. Dreaming is not like thinking about things.You have feelings during dreams. You may feel happy or angry. You feel fear if you have a nightmare.

Your memories may have something to do with your dreams. Dreams are often like stories that stop before they are finished.