Board Thread:General Discussion/@comment-3257939-20140521172812/@comment-3146930-20140523040330

A good example of this is the book Warm Bodies (not the movie). In it, zombies are able to have thoughts of their own and when it comes time to feed, they know their limitations and will usually avoid massively populated areas of humans and go after the smaller groups with less numbers. Grimm have shown to be at least mildly intelligent for animals, as the Nevermore destroyed the escape route over the bridge and the Ursa Yang fought gave each other a questioning look when Yang activated her Semblance. Even if Grimm are drawn to the souls of the living, they may also be smart enough to know what places not to attack as more numbers means a better chance of survival overall.

Just as a side note, I believe there is something like a Halo Gravemind for the Grimm, but it was defeated after the first war and now lays dormant waiting for the right moment when humans are so busy fighting themselves, that they overlook the Grimm.