The story takes place in modern times at the Fitzgibbon farm. The Fitzgibbon house serves as background for the homes of the animals that live nearby.

The animals' abodes are vividly described. Mrs. Frisby and her children, a family of mice, live in a "slightly damaged cement block [that] . . . lay almost completely buried" in Mr. Fitzgibbon's field. The furnishings of this house are "bits of leaves, grass, cloth, cotton fluff, and other soft things Mrs. Frisby and her children had collected." The Frisbys stay here during the winter, when living in the woods becomes too harsh because of the scarcity of food. The farm provides Mrs. Frisby and her family with a home and there are leftover crops for food, but it is also a dangerous place. Mice never forget that this is cat territory, and when Mr. Fitzgibbon begins plowing in the spring "no animal caught in...