You are essentially hearing their thoughts. Their grammar might sound perfect because of that translation, but they are not having high level thinking going on. They notice things, and they don't know the context of things. They are not actually speaking in common. Everyone around you hears them barking at you or mooing or whatever sound they normally make.
Perhaps, then I feel like the game is not conveying this convincingly. What I mean is I understand that it is me who is speaking the language of animals and they are not talking common but the translation is too sophisticated, too intelligent. Like I said it could be like:
''Bark'' translation: ''Me want food.'' Not ''Oh, I feel like a piece of fine lamb would be nice at this hour.''
