Rats existed as fauna within the depths of the city-planet known as Coruscant. The specimens inhabiting the Level 1782 junkyard were of a notably increased size. Conversely, Tatoo-rats inhabited Jabba the Hutt's palace located on Tatooine. The numbers of rat individuals were at times controlled by the presence of cats.
The term "rat" also functioned as an insult directed towards sentients.