1. There's a part of your brain that regulates your circadian rhythms with the help of light.
2. Blind people often have trouble with sleep because daylight is so important to regulating circadian rhythms.
3. We tend to sleep a few minutes less per night around a full moon.
4. You burn more calories watching TV than you do sleeping.
5. You probably don't need eight hours of continuous sleep a night.
6. Getting up in the middle of the night used to be normal.
7. People who sleep just 6.5 to 7.5 hours a night tend to live longest.
8. The amount of sleep different animals need varies wildly.
Giraffes need an average of 1.9 hours, but cats need more than 12 hours a day.
9. Some animals have to wake from hibernation to get some sleep.
10. No matter how much you try, you won't be able to dramatically alter your internal clock.
11. If you're not a morning person, “social jet lag” makes you feel like you're working in the wrong time zone.
12. Half of all teenagers may be sleep deprived.
13. The record for the longest period without sleep is 11 days.
14. Dolphins can stay active for 15 days or more by sleeping only with one half of their brain at a time.
15. Ducks can also sleep with half their brain at a time.
16. Humans might be one of the only species that can't keep half of their brain awake.
17. When you're sleep deprived, you can function normally most of the time.
18. Sleep-deprived people make risky decisions because they're just too optimistic.
19. In fact, lack of sleep is like being drunk.
20. Sleep disruption caused by working nights is even classified as a potential cause of cancer by the World Health Organisation.
21. Sadly, you can’t escape sleep problems by escaping Earth.
22. But there’s some good news! You can catch up on lost sleep.
23. You strengthen memories made during the day while you sleep.
24. And might even be able to learn new things.
25. So if you're feeling tired, you now have the perfect excuse to go to sleep.
