If the animals could speak, they would only speak of visible realms; of the mineral realm, the plant realm, and the animal realm. They would consider themselves as the highest visible realm. That the animals see the human being like a human being sees the other is only a prejudice.
Human beings are of a supersensible, ghostly existence to the animals; If the animals had only such a perception as we have, the human beings would be as invisible for them as the realm of angels is for the human beings. Only because they have a certain kind of dreamy clairvoyance, the animals see the human being as a ghost, as a supersensible being. The human being can have no idea of the image which an animal has of him.
Source: Rudolf Steiner – GA 159 – The Mystery of Death – Prague, 13th May 1915