why do we sleep at night, get tired

Question: why do we sleep at night, get tired
- Keywords:
  night,
  sleep,
  tired
Asked by Ellie.C to Hephzi, Imogen, Jen, Jennifer, Tom on 10 Mar 2015.
- Jen Machin answered on 10 Mar 2015:
  
  Our bodies do lots of repair work at night when we sleep. One other thing that happens when we sleep is that our brain sorts through the information we have learnt during the day, and helps some of our new memories grow stronger. Some people think this might be why we have dreams at night 🙂
- Thomas Barrett answered on 10 Mar 2015:
  
  Sleep is really important to the body. It is believed to help form memories of the day, repair the body and many other things. As Jen says some people think dreams form when your brain tried to make sense of everything that went on in the day and organizes it all.
  
  We sleep at night as that is how we evolved. The different wavelengths of light that are more abundant towards the later part of the day signal to our brain that it’s time for bed. That is why some people worry about looking at a computer screen late at night as the light from the screen tells your brain to stay awake.
  
  Not everyone sleeps at night however. I do know a few people who are nocturnal and sleep in the day and wake up at night 😛

Question: why do we sleep at night, get tired