Boltz is probably one of the more expressive wolves in terms of facial expressions.  The most powerful expression that will elicit a response from the packmates is the direct eye stare.  In this post’s photo, he stops a confrontation with Axel causing him to avert his gaze.  These kind of non-physical interactions are great ways for social packmates to understand the limits and tolerances of behaviors, especially from exuberant two year old wolves.