Animals are NPC creatures that can be taken control of by ghosts. They are found on the station at the start of a round or created through scientific means. They have limited ability to interact with the environment, usually can only speak to other animals, and are unable to hurt objects or people, with the exception being sentient animals spawned by a random event.
If you're a Ghost, either from dying or being an observer and your 'Repsawnability' is on, you can choose to become an animal anywhere on the station, such as a pet or random animals like mice by using the Respawn as NPC verb in the Ghost menu.
Unfortunately, there is not much to do, as you can't interact with anything in most cases. Still, you can communicate with other animals, wander around the station, and go on a grand quest!
Pets will spawn in the offices of the department they're assigned to. For the case of mice however, you'll usually spawn near a random vent, in Xenobiology, or in someone's office. This can be sometimes result in your death if you spawn on a vent in an airless room. Tiny animals can vent crawl, which is achieved by Alt+Clicking a vent. Small creatures are also able to use the Hide verb in the Animal menu to crawl under tables and object, allowing them to get out of sight or more easily escape attackers.
Remember that you are in fact, an animal. But you can still play around with the crew and hopefully not be run over by mindless greytiders who appear very often! Go explore the station, meet up with the other pets,
plot against play with your owner, or try to undertake a task that'd be difficult for an animal to achieve.
You can be instantly killed by pretty much anything. Animals have very low health, no means of fighting attackers, and can only run to avoid danger. Being unable to call for help also means you'll likely have no one to defend you. The life of an animal is full of dangers!
If attacked, try your best to get away. You're able to walk over tables unimpeded, and tiny animals can use vent crawling. (Just don't use scrubbers to vent crawl. They have no air.) If you're one of the station pets, running to your owner may get them to come to your defense.
Return To The Dead
It's possible to return to ghost form if you happen to get bored or if you're killed. Be aware that using the Ghost verb may have your Repsawnability disabled.