The questioner for
got the question wrong, so the response was wrong too.
The question isn't do animals feel pain, because the consensus among animal behavorists is that they certainly do experience pain sensations which are in almost every way akin to the pain which humans feel.
The correct question is whether animals can experience "suffering", and by extension, whether it is possible to "torture" an animal.
For example, if someone were to step on your toe accidentally, a human (or animal) would feel a sensation of pain. But the pain would be momentary, and you wouldn't "suffer" from it unless you thought they had done it on purpose or vindictively. For that matter, a human can be harmed or "suffer" from some real or imagined act done to them when there is no pain (or even when there is pleasure) associated with the event.
The argument being made by some researchers is that all animals (including apes, dolphins, etc.) except humans lack the...