Board Thread:Speculation House/@comment-24994749-20140808215337/@comment-73.42.187.52-20141210144557

^the point is, if you watch the show the evidence still seems to point towards the possibility. I myself didn't think it likely until I went back through the series and looked for a faunus being attacked, it just doesn't happen unless you count the moments when a faunus(Blake) looks similar to and is standing beside humans or times when the grimm are disturbed by the explosions from the train cars.

as for how grimm could sense them, the grimm are completely unknown, for all we know, they could be the ghosts from FF: the spirits within, sharks can sense blood for miles, they sense negative emotions... we just don't know.