I never heard a sound effect to go with that animation (playing the US Xbox release). Checking it now with the music off and sound effect volume up, the creature can randomly go though the 3 idle animations fairly quickly (sound effects were fine for sitting and scratching, as well as sniffing and digging) if I stood perfectly still in a moderately confined space.
When actually playing, however, the creature was rarely standing around in my field of view if I ever stopped to grab loot or break crates, etc, and even when he was visible, the creature rarely stood around in one spot. It did wander through the background of a couple conversations, etc, but not anywhere near the frequency you seem to be getting.
