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
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
The strangers in your dreams are actually people that you've seen in real life.
50
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
Honeybees never sleep.
276
Bats sleep 18-20 hours per day.
5