A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
Lack of water is the #1 trigger of daytime fatigue.
148
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
Honeybees never sleep.
276
People who sleep late have more mental stamina and can outperform early risers.
33