The animals communicate with one another through shrill whistles and squeaks.
He later studied how animals can communicate through odors.
Then he realized with some horror that the animal was communicating with the Mayor!
A major story change made for this movie version is that while all the animals communicate with each other, they do not talk to the humans.
Only humans use language, though many other animals communicate in various ways.
Almost all animals do communicate between themselves with sounds, smells, gestures and so on.
The animals could communicate with body language, tail wagging.
Thus he says, "It is easy enough to show that animals communicate, but this is a fact which has never been doubted.
Many animals communicate information about themselves without necessarily changing their behaviour.
Many animals, however, communicate at levels well above this (or below it, in the case of elephants, for example).