Cows can sleep standing up, but they can only dream lying down.
745
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Tigers can see 6 times better at night than humans.
305
Bats sleep 18-20 hours per day.
5
A dork is a whale's penis.
327
A cat rubs against people not only to be affectionate but also to mark out its territory with scent glands around its face. The tail area and paws also carry the cat's scent.
293