The Secret of NIMH is an animated movie directed by Don Bluth and released by his studio United Artists in 1982. The movie was based on Robert C. O'Brien's children's book "Mrs. Frisby and the Rats of NIMH". (The main character's name was changed to "Brisby", so that its audiences would not take its sound for the Frisbee toy.) Bluth began the idea of creating this movie after disagreement with Disney over "The Fox and the Hound". Before that he worked with the previous Disney animated movie which was also about mice: "The Rescuers". Later he made another animated movie about mice called "An American Tail", which came out in 1986.