A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
You burn more calories sleeping than you do watching television.
348
There's a love mattress that is specifically designed for couples who sleep on each other's arms.
12
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
Lack of water is the #1 trigger of daytime fatigue.
148
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22
Honeybees never sleep.
276