A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
Lack of water is the #1 trigger of daytime fatigue.
148
A new parent will lose about 1055.6 hours of sleep in the first year of their child's life - almost 44 days!
6
The average cat sleeps about 2/3 of the day.
203
"Dysania" is the state of finding it hard getting up out of bed in the morning.
33