The party is thundering through the dungeon corridors trying to be quiet. Oh they believe they are quiet. Hell, the thief made his move silently roll, but with nearly a ton of metal armor, weapons and the hundreds or thousands of coins they are dragging along being quiet in a confined room/corridor is not an easy feat. And when the party starts beating on one of the dungeon denizens then the gig is up.
When writing adventures there is a lot of encounters where the creatures are surprised. They wait in stasis for the players to activate them so to speak. If there is a group of bandits that get monkey stomped in one room and the there are a bunch more in the next three things should happen. The bandits join the frey, the bandits set up an ambush to surprise the players as they come in or grab their family photo albums and get the hell out of there.
Player's make a lot of noise. They can't help themselves. So as GMs out there, how do you handle the noise factor of your players? When they are bashing in a door does it alert a portion of the dungeon creatures? Does it make them scurry to the noise? Set up an ambuch? Or do you keep the critter in stasis? I know a lot of it depends on the type of creatures that populate you place, but most of the critters have some sort of intelligence and mobility, what do they do when they players come knocking?