If you're a Ghost, either from dying or being an observer and your 'Repsawnability' is on, you can choose to become a Mouse.
Unfortunately, there is not much to do, as you can't interact with anything. Still, you can communicate with other mice, crawl through vents, and go on a grand quest for cheese!
You'll usually spawn near a random vent. It's best to stay as close to these vents as possible, as they can prove a useful means of escape from any pursuer.
Remember, you are just a rodent (at least, humans think so). You are not allowed to let humans know that you are intelligent.
You must plan your grand overtake of the whole station! The humans will pay for their mousetraps, cats, and big stompy feet!
You can be instantly killed by mousetraps, cats, or being stomped on. The life of a mouse is full of dangers!
Hiding is your best friend!
Return To The Dead
It's possible to return to ghost form if you happen to get bored, if you are killed, or the cheese has gone missing.