Normal on Survivor (can't remember on creative but I think it doesn't matter anyway).
What I love about this is it's mob proof. The only way in or even around is the front door, and they usually spawn at the mountain bottom so I can just snipe them with bow and arrows and they just wander around clueless.
I played some survivor today too. Explored the rest of the dungeon. Fell through a hole and ended up in caves with pieces of dungeon scattered all over the place, it had a big "ruins" feel to it. Found lots of redstone, iron, lapis, and gold but there were also lots of mean mobs (I had no armour). I made it out... barely and was never so happy to see the sunshine.