In the Bradbury story, There Will Come Soft Rains, the little robotic mice clean the house. They represent, with their frantic motions, a household that was used to being run in a timely manner, with order and direct intention. This also indicates that the people who used to live there were well off and used to conveniences that technology offered. But long after the people are gone, the mice toil for no one...slaves to their routine and programming.
