Why do we sleep? Sleep gives your body and mind a rest. You feel fresh when you wake up.

Sleep helps children grow. It also helps your brain work well.

You may think your brain turns off when you sleep. It does not. Your brain and body keep working while you sleep.

We have dreams while we sleep. Dreams are pictures, thoughts or feelings that come to us as we sleep.

When the sun goes down, your brain starts making melatonin. Melatonin is a sleepy-time hormone.

How much sleep do you need? Children from 6 to 12 years old need 9 to 12 hours of sleep a day.

Going to bed and getting up at the same time every day helps. So does the same bedtime routine. Both help children fall asleep more easily.

Enough sleep can help you feel happier and in a better mood.

Enough sleep helps you get sick less often. Sleep helps the body fight off germs.

Animals need to sleep too.

Words to know

• melatonin: sleepy-time hormone
• hormone: body helper
• routine: daily habit
• germs: tiny sickness-makers