The question of animal consciousness is complex, but it's clear that mammals can reason and feel emotions. Some (the great apes) are capable of inferring mental states in others, and are capable of consciously trying to deceive others.
I believe animals are innocent, since only man is recorded as having a knowledge of good and evil. Yet dogs and apes seem capable of understanding fairness. (dogs trained to do a trick for a treat, will stop performing, if they see another dog being given a better treat for the same trick).
How do we know any other entity is conscious? We can't absolutely know.
"And if I were to look inside your head, I would also see nothing but electrons," replied Klapaucius. "Come now, don't pretend not to understand what I'm saying, I know you're not that stupid! A phonograph record won't run errands for you, won't beg for mercy or fall on its knees! You say there's no way of knowing whether Excelsius's subjects groan, when beaten, purely because of the electrons hopping about inside—like wheels grinding out the mimicry of a voice—or whether they really groan, that is, because they honestly experience the pain? A pretty distinction, this! No, Trurl, a sufferer is not one who hands you his suffering, that you may touch it, weigh it, bite it like a coin; a sufferer is one who behaves like a sufferer! Prove to me here and now, once and for all, that they do not feel, that they do not think, that they do not in any way exist as being conscious of their enclosure between the two abysses of oblivion—the abyss before birth and the abyss that follows death—prove this to me, Trurl, and I'll leave you be! Prove that you only imitated suffering, and did not create it!
"You know perfectly well that's impossible," answered Trurl quietly. "Even before I took my instruments in hand, when the box was still empty, I had to anticipate the possibility of precisely such a proof—in order to rule it out. For otherwise the monarch of that kingdom sooner or later would have gotten the impression that his subjects were not real subjects at all, but puppets, marionettes. Try to understand, there was no other way to do it! Anything that would have destroyed in the littlest way the illusion of complete reality would have also destroyed the importance, the dignity of governing, and turned it into nothing but a mechanical game...."
"I understand, I understand all too well!" cried Klapaucius. "Your intentions were the noblest—you only sought to construct a kingdom as lifelike as possible, so similar to a real kingdom, that no one, absolutely no one, could ever tell the difference, and in this, I am afraid, you were successful! Only hours have passed since your return, but for them, the ones imprisoned in that box, whole centuries have gone by—how many beings, how many lives wasted, and all to gratify and feed the vanity of King Excelsius!"
Without another word Trurl rushed back to his ship, but saw that his friend was coming with him. When he had blasted off into space, pointed the bow between two great clusters of eternal flame and opened the throttle all the way, Klapaucius said:
"Trurl, you're hopeless. You always act first, think later. And now what do you intend to do when we get there?"
"I'll take the kingdom away from him!"
"And what will you do with it?"
"Destroy it!" Trurl was about to shout, but choked on the first syllable when he realized what he was saying. Finally he mumbled:
"I'll hold an election. Let them choose just rulers from among themselves."
"You programmed them all to be feudal lords or shiftless vassals. What good would an election do? First you'd have to undo the entire structure of the kingdom, then assemble from scratch ...""And where," exclaimed Trurl, "does the changing of structures end and the tampering with minds begin?!" Klapaucius had no answer for this, and they flew on in gloomy silence, till the planet of Excelsius came into view.
Stanislav Lem The Cyberiad; The Seventh Sally or How Trurl's Own Perfection Led to No Good