I'm assuming their only hostile in the, curosity killed the cat, which would be to look at them, then if you look away, they won't care where your going, because, well, they got SHIT TO BUILD, I still think it would be Neat-O if they purposely built forest cities, not only that, but if one would be there forever, like a guard to the empty nothing of which it lives for. So, my speculation, they ONLY attack when your cursor is on them, thus like in real life, you'd be scared at the mere SIGHT of them and turn your head in speculation of the monster still being there, their face being the last sight, they will carry some blocks around to play with, this either means they'll be sophisticated and build, mine into the earth by moving the blocks out of the way, or simply just being stupid and just moving blocks around. What would be more cool if their eyes started to change color based on their pissed level, from white to a blood red, again, assuming they will insta shot you like in the video, it would be useful to know when to back your shit up and leave, their also apparently passive, but when hit, or looked at, WILL GET PISSED and more or less insta shoot you, also, they'll have incredible speed on your side, and I wouldn't count on them being rare, since notch LOVES to fuck with people.