Why do we sleep?
Every night your body and brain get busy while you sleep. Find out what happens, why we dream, and what helps you sleep well. Then keep a sleep diary.
Read
Everybody needs sleep. Children aged 6 to 12 need about 9 to 12 hours of sleep every night. That is more than most grown-ups need.[3][1]
When you sleep, your brain is not switched off. It is busy tidying up and helping you remember what you learned during the day.[1]
In deep sleep, your heart beats slowly and you breathe slowly. Your body grows and repairs itself.[2]
In another kind of sleep, called REM sleep, your eyes dart back and forth under your eyelids, and you dream! Your arms and legs stay still, so you don't act out your dreams.[2][1]
Your body has a clock inside. When it gets dark, your body makes something called melatonin that makes you feel sleepy.[1]
Going to bed at the same time every night, keeping your bedroom dark and quiet, and leaving tablets and TV out of the bedroom all help you sleep well.[3][1]
Try it: My sleep diary
You need
- A sleep diary sheet (the worksheet)
- Crayons or pencils
- A grown-up at home to help read the clock
Safety
Your diary is private: you never have to show it or tell anyone your times. There are no right or wrong answers.
What to do
- At bedtime, draw a moon 🌙 and ask a grown-up to write the time.
- When you wake up, draw a sun ☀️ and write the time (with help).
- Draw a face to show how you feel in the morning: happy, OK or tired.
- Do this for 5 nights.
- Back in class, count the hours together. Did you sleep 9 to 12 hours? Did you feel different after longer nights?
Play: Sleepy or wide awake?
Does this help you fall asleep, or does it keep you awake? Tap the right group.
Your best score is kept only on this device. Nothing is sent anywhere.
Quiz
Other ages: Ages 10–11 · Ages 15–16