The actual ability to pick up a mouse off a desk can't be done all the time and can only be done if you have 2 specific tasks: "Where's the janitor?" or "Mouse Thief."

However, once you actually throw the mouse away, the task is completed, and you lose the ability to pick up mice.

But there is a third condition, and that is if there is no mouse on your desk, and this is where the real technique comes in.

If you don't have a mouse on your desk, such as in the case someone steals yours, then the game will let you pick up mice in order to replace the one you lost.

Therefore, why not steal your own?

To begin, you need to work, doing tasks until you get either Mouse Thief or Where's the janitor? Instead of taking someone else's mouse, you need to take your own and throw it away. You have successfully triggered the ability to pick up mice infinitely, and now your reign begins.

Map knowledge is important, as you want to always know where the closest trash can is. It definitely helps if the lobby has sprinting enabled, as you can clear out a whole annex in under a minute.

The most IMPORTANT thing is to get a handle on the mouse movements required to quickly place a mouse in the trash can and then "empty" the trash can. This will delete the contents and disallow the angry owner from getting their mouse back, sending them to the storage room.

Now that you understand how to accomplish this, you're free to scoop up every mouse in the office and dump it in the garbage.

The only caveat to the previous segment is if you are a Janitor, which usually happens after you've stolen enough mice and have shed your corporeal form and ascended to godhood.

The Janitor actually is kind of worse for stealing mice. Seeing as you don't have a desk of your own, you are unable to trigger the infinite mice-stealing effect and have to rely on the constant "Where's the janitor?" task you receive.

However, stealing one mouse every 30 seconds is very lame, and this is where the Janitor has a bit of a different strategy.

During the inevitable meetings, you need to run around and pick up as many mice as possible, and then drop them on the floor. This won't trigger the "Where's the janitor?" task, and once you've dropped them all, you can gather them up and throw them away very quickly.

Stockholm is the best map.

Naturally, the easiest fix to having your mouse stolen is to go get a new one from the box, but what if the box is nowhere to be found?

Thanks to the addition of an exterior to the new Stockholm map, you can very easily hide all the mice boxes outside. The easiest way to do this is to carry them either through the Kitchen to the stairs outside or the door in the Ladies Bathroom downstairs. Hide them anywhere in this alley, lock the doors if you can get your hands on the keys, and then begin looting and pillaging the office.