Factual error: During the conversation about plowing, the shrew asks Mrs. Frisby, "Remember in the spring of sixty-five? He plowed on the eleventh of March, and on a Sunday at that." In 1965, March 11 fell on a Thursday, not a Sunday.

Factual error: During the conversation about plowing, the shrew asks Mrs. Frisby, "Remember in the spring of sixty-five? He plowed on the eleventh of March, and on a Sunday at that." In 1965, March 11 fell on a Thursday, not a Sunday.

More mistakes in Mrs. Frisby and the Rats of NIMH