in the book.

At tea-time, when the dog, Jip, came in, the
parrot said to the Doctor, "See, HE'S talking to
you."

"Looks to me as though he were scratching
his ear," said the Doctor.

"But animals don't always speak with their
mouths," said the parrot in a high voice, raising
her eyebrows. "They talk with their ears,
with their feet, with their tails--with everything.
Sometimes they don't WANT to make a
noise. Do you see now the way he's twitching
up one side of his nose?"

"What's that mean?" asked the Doctor.

"That means, `Can't you see that it has
stopped raining?'" Polynesia answered. "He
is asking you a question. Dogs nearly always
use their noses for asking questions."

After a while, with the parrot's help, the
Doctor got to learn the language of the animals
so well that he could talk to them himself and
understand everything they said. Then he gave
up being a people's doctor altogether.