A squirrel can get angry or crazy, but it stays a squirrel. It squeaks and bites, it doesn't learn how to fly or conquer half the planet. Madness alone can only get you so far.

Because as an animal, a squirrel has to work with what it sees. Humans have words. With words, everything we've ever encountered can be connected together in a controllable system. We can summon every idea in our head at will, whenever we want.

A word can have several meanings. The word "animal" is sometimes used for moving creatures that aren't human.