A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
A new baby usually deprives each of it's parents around 350-400 hours of sleep in the first year. That is one entire nights sleep per week, per parent.
194
47% of people have a nightmare at least once a month.
186
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
Some people have a "natural alarm clock" allowing them to wake up when they want. This is actually caused by a burst of the stress hormone adrenocorticotropin.
15
44% of kids watch television before they go to sleep.
106