A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The average cat sleeps about 2/3 of the day.
203
Sleeping on the job is acceptable in Japan. It is viewed as exhaustion from working hard. Some people fake it to look committed to their job.
57
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
If you hold farts in during the day, they'll just come out when you sleep.
16
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
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28