19 Fascinating Facts about Sleeping

Everyone does it and yet sleep is still something of a mystery. How many of our fascinating facts did you know?

1. There are different levels of sleep, including REM (rapid eye movement) sleep, which is when we dream

2. Not everyone remembers their dreams but we’re most likely to remember them if we are awoken during REM sleep

3. Many animals sleep standing up

4. Humans can sleep with their eyes open: animals often sleep with a third eyelid covering their eyes, giving a milky appearance to the eye.

5. There are many theories about the purpose of dreams, including that they are a way of processing the events of the day and storing useful information in our memories

6. On average, we spend an estimated 25 years of our lives asleep

7. Shift working disturbs our natural sleep patterns and is not considered good for our health but some people adapt more easily than others

8. In countries where daylight hours are very short during winter, people are inclined to sleep much longer – and the reverse is true in the long daylight hours of summer

9. Babies and children need more sleep than adults to grow and develop

10. Some studies have claimed that teenagers function best if they wake late in the morning and go to bed later than adults

11. We learn to anticipate the time that we normally get up and release a hormone that is associated with stress at about that time, even without an alarm

12. Birds are able to allow half their brain to sleep, while the other half processes information that protects them against attacks by predators

13. Women need an hour’s more sleep than men

14. The quality of sleep we get after drinking alcohol is not as good as usual, which contributes to our feeling worse than normal on waking

15. We sleep best when the room temperature is between 18-30C (23-25C in old age)

16. Certain disorders allow you to get up and move around, speak and even commit crimes, while apparently still asleep

17. 41% of us sleep in the foetal position, with our legs curled towards our bodies. Studies suggest that these people tend to have warm-hearted personalities

18. One in four couples sleep in separate beds

19. Giraffes sleep less than 2 hours per day in short bursts, whereas koalas sleep 22 hours a day