Signs

Koko is a gorilla that scientists taught how to use sign language.
She communicates with her researchers, has owned cats as pets, and likes it when people visit her.
Scientists taught other animals to use sign language.
Chimpanzees and orangutans use it, although they’re better with pictogram boards.
Symbols which represent things like food and sleep and hello.
And many herding dogs know hand signals, too.
Follow. Chase. Home.
One scientist tried to teach sharks how to use sign language.
But all they ever understood was “Tear me into small bloody chunks.”
I guess that makes the sharks really smart.