The family bio says that the cats have been travelling together for a long time, and that they want to see if Mesa Flats is really a paradise for cats like them. The cats can be found in the family bin without any funds, so that means they must move in with another househould that also consistists of at least one Sim because the cats cannot take care of themselves. This family and the Crittur family from The Sims 2: Pets are the only families that only have pets as residents.