User blog comment:Deafro/What makes RWBY Interesting/@comment-15108745-20130830202410/@comment-16763585-20130831144756

True we don't have concrete facts about Dust or Aura, but there are enough small details to form a hypothosis. It is quite possible the theory could be entirely wrong, and it may very well be that all the stuff I was looking at really didn't matter to the writers. I can't be absolutely sure until more information is given on the subject, but I can be 85% confident that the facts are pointing in a series of directions, one of which I really hope is the case.

As for the hive mind theory, the Grimm don't need to be cunning, they need to have priorities. Really I would rationalize it saying they couldn't run because they were starving. They've already eaten all the animals, so the humans are all that's left, and losing here means being unable to eat later down the line. Even then however I would think they'd limit their motions to a bare minumum to conserve energy.