Does their language have to be as complex as human languages, or is it enough to know that an animal is e.g. in pain or looking for food?

@12c498e Good question. I’d assume complexity of communication is limited by the intelligence of the animal in question. So for animals of lower intelligence the best we could expect may be what you’ve mentioned (feeling pain, searching for food etc.) .

But for animals of higher intelligence (e.g. Dolphins) I’d expect more complex communication albeit less complex than human communication.