1) Some wolf packs have been known to preside over territories as big as 1,000 square miles.

2) The longest-lived vertebrate creature is the Greenland shark. Some have been estimated to be more than 500 years old.

3) Tigers have white spots on the backs of their ears that mother tigers use to communicate with their cubs. They act as a flasher to the cubs to signal movement.

4) Hippos have the largest mouth of any terrestrial animal and can open their jaw to almost 180°.

5) Hippos also have enormously long tusk-like teeth. The longest hippopotamus tooth ever recorded was an incredible 48 inches long.

6) Because it holds its tail behind it, arched upward over its back, the squirrel is said to take its name from a Greek word that literally means “shadow-tail.”