When cats are happy, they may squeeze their eyes shut.
10
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
A tortoise named Adwaita lived to 255 years old. To put it into perspective, he was born before the United States of America existed and his death was announced on CNN (1750-2006).
12
Leonardo Da Vinci loved animals so much that he used to buy caged animals at the market just to set them free.
57
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14