Monster Hunter Tri is full of all sorts of wild new content, including some more subtle monster/hunter/environment interactions. Unity member, MoisesL, being an avid Monster Hunter fan, has taken a video of his experience in the environment of one of the new areas in Tri. 

The monsters in Tri don't always immediately attack you. In fact, most of them have their own little daily lives to go about, and will do so if you don't provoke them. Check out one bit of this in Moises' video with some insects gathering some juice from mushrooms.