When cats are happy, they may squeeze their eyes shut.
10
Sharks have been on the planet longer than trees.
14
Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
When the "Elephant Whisperer" Lawrence Anthony died, a whole herd of elephants arrived at his house to mourn him.
25