Good question. Since we really can't ask them and expect a verbal answer, we can observe them.
But, are our consciousness' really that much different from a beast or insect? While humans are without a doubt capable of much deeper thought, and better suited for a more complex life, in the end, survival of self and sometimes the herd, and some sort of comfort are sought after be all forms of life. For all our understanding of the brain allows, it is possible that our own "emotions" are artificial, and preconditioned.