|Directed by||Phil Karlson|
|Produced by||Mort Briskin|
|Written by||Gilbert Ralston|
|Music by||Walter Scharf|
|Studio||Bing Crosby Productions|
|Distributed by||Cinerama Releasing Corporation|
|Running time||94 minutes|
A lonely boy named Danny Garrison befriends Ben, the rat leader of the swarm of trained/telepathic rats found in Willard. Ben becomes the boy's best friend, protecting him from bullying and keeping his spirits up in the face of a heart condition.
However, things gradually take a downward turn as Ben's swarm becomes violent, resulting in several deaths. Eventually, the police destroy the rat colony with flame throwers, but Ben survives and makes his way back to Danny. The film closes with Danny, tending to the injured Ben, determined not to lose his friend.
- Lee Montgomery as Danny Garrison
- Joseph Campanella as Cliff Kirtland
- Arthur O'Connell as Bill Hatfield
- Meredith Baxter as Eve Garrison
- Rosemary Murphy as Beth Garrison
- Kaz Garas as Joe Greer
- Paul Carr as Kelly
- Richard Van Vleet as Reade
- Kenneth Tobey as Engineer
- James Luisi as Ed
- Lee Paul as Careu
- Norman Alden as Policeman
- Scott Garrett as Henry Gray
- Arlen Stuart as Mrs. Gray
- Richard Drasin as George
Theme song 
The film's title theme song of the same name is performed by Lee Montgomery in the film and by Michael Jackson over the end credits. Jackson's recording of the song became a #1 pop hit single. Later included on Jackson's album of the same name, "Ben" won a Golden Globe Award for Best Original Song and was nominated for an Academy Award for Best Original Song (it lost to "The Morning After" from The Poseidon Adventure).
The song is calm and mellow, which contrasts with the horror content of the film. A live recorded version was released on the 1981 album The Jacksons Live! and eventually appeared on Jackson's Number Ones album in 2003.