When a dog growls at you, is it angry? When a squirrel flees up a tree at your approach, is it fearful? When an elephant stands for days on a spot where another has died, is it grieving?
The big idea: do animals have emotions?

When a dog growls at you, is it angry? When a squirrel flees up a tree at your approach, is it fearful? When an elephant stands for days on a spot where another has died, is it grieving?