Board Thread:Speculation House/@comment-4830106-20130823152544/@comment-99.18.230.59-20130825061847

I would guess, that if the Grimm have hive minds, there may need to be a 'critical mass' for it to manifest. For example, there are enough Grimm in the Emerald Forest to train with, but insufficient to actually have them hit that critical mass for a hive mind.

And it might be a critical mass of power, numbers, or a sliding scale between the two. IE: if it takes 10,000 Grimm factors to awaken the hive mind, it could take 10,000 Grimm each with a 1st level factor, or 10 really nasty Grimm each with a 1,000 level factor. Or any combination that totals 10,000 (5,000 1st level, and 5 1,000th level).