Animals and humans feel emotions very differently, so much so that it makes human emotions harder to study.  However these feelings and emotions come from the same basic "survival circuits" in the brain, which are the same in all mammals.  In truth, researchers tend to fake their understanding of emotions. They depend on insights from personal experiences to determine that some mental states have certain ''feelings'' associated with them, which we call "emotions."  Instead of trying to compare animals and humans researchers should study the "survival circuits" behind behaviors. Studies in animals can find survival circuits universal to mammals, like fear and hunger.