Monster Houses
What is a monster house? No it is not a house of monsters or a bunch of monster sharing a house.In Pokemon Mystery Dungeon Blue & Red it is when a bunch of Pokemon randomly fall from the sky into the room you just entered. That is called a monster house.
Sometimes 5 Pokemon will fall other times 10 maybe more. It's good to link moves or have moves like thunderbolt which hit all foes in a 1-tile range. This will help you to beat the Pokemon faster.
Monster houses can be really annoying at times but it's also good for some exp.