‘The Secret of NIMH’ Scarred A Generation Of Children (And Has An Even Weirder Backstory)

Those who grew up in the 1980s may fondly remember The Secret of NIMHIt's a lovely tale about a mouse named Mrs. Brisby who just wants to protect her family and, with the help of the great owl, manages to rally a group of intelligent rats led by the enigmatic Nicodemus to help her - only, it's much more than that. The film is dark, it's intense, and it covers some serious issues most adults aren't comfortable discussing in polite conversation. After all, NIMH is the National Institute for Mental Health, and that's not something you're aware of when you watch this film as a child.

The movie was based on a book titled Mrs. Frisby and the Rats of N.I.M.H, and it's got an even weirder backstory than the Don Bluth animated film. Regardless, the movie is beloved and is an exceptional presentation of the animation talents of Bluth and his team, which is one of the many reasons adults and children still love the movie to this day.


  • The Story Was Inspired By A Real-Life Government Lab Study About The Demise Of A Rodent Utopia

    In a bid to study population density and its effects on behavior, researcher John Calhoun devised a series of rodent utopias that he would manipulate in various ways. He constructed multi-level living spaces, little rodent condos, and public squares, and he observed the rats' behavior to see how changes in their population density affected their interactions with one another - and it wasn't pretty.

    The experiment showed that different rats and mice behaved in various ways depending on the amounts of food, water, and viable sex partners available to them. Those he described as "the beautiful ones" would do little but groom and sleep all day, while others would copulate and eliminate one another. It was an interesting study, and he published it in a 1962 issue of Scientific American.

    The study detailed population density so well, it helped inspire numerous fictional works. In addition to the book, Mrs. Frisby and the Rats of N.I.M.H, it gave rise to movies like Soylent Green as well as comics like 2000AD.

  • The Study’s Author Used Quotes From The Book Of Revelation And Drew Parallels Between Rodent And Human Societies
    Photo: Cat Calhoun / Wikimedia Commons / CC BY-SA 3.0

    The Study’s Author Used Quotes From The Book Of Revelation And Drew Parallels Between Rodent And Human Societies

    The purpose of Calhoun's study was to see how populations of rats and mice would behave around one another when the density of that population increased while the resources diminished or stayed the same. In this, he was trying to ascertain how humans would react in the same situation, and it came at a time when people were growing more and more fearful of moral decay in the face of urban sprawl.

    In the paper he published, Calhoun often drew parallels between human and rodent societies, but more interesting was his continued use of quotes and references to the Book of Revelation, which describes Armageddon in the New Testament. Specifically, he wrote that the utopia had devolved into hell.

    He often quoted passages directly from the Book of Revelation, and he italicized some words to give them more impact: "To kill with the sword and with famine and with pestilence and by wild beasts."

  • The Rodents In The Film Are Trying To Escape Being Exterminated

    There are several threats looming over Mrs. Brisby (changed from the novel's Mrs. Frisby) and her family throughout the movie. In addition to the predatory cat, the questionable allegiances of some of the rats, and an owl that gets a bit too close for comfort, she must also deal with the fact that her child is sick and cannot be moved.

    Moving becomes a significant issue, as the farmer whose land the rodents live on is getting his equipment ready to plow the land. Plowing will ruin the Brisby home and eliminate any mice inside, and Mrs. Brisby's inability to move her son for fear of ending his life becomes the driving focus of the film.

    Once the plow is repaired, all bets are off, and any rodents in the field will be violently slain, so Mrs. Brisby has to turn to the rats of the Fitzgibbon farm to save her family.

  • In The Film, The Caged Rats Are Shown Being Injected With An Unknown Substance

    John Calhoun's study wasn't met with applause and cheer, and many people considered the work he did with mice and rats to be somewhat despicable. The ones who thought his experiments cruel might have also helped influence the book, as the scientists working at NIMH in the novel aren't presented as anything other than horrific monsters.

    In the movie, this is taken a step further via a flashback sequence, which shows human hands holding rats as they inject who knows what into their bellies. The results of these experiments could be seen in the increased intelligence of the rats, but it's clear they recall the whole ordeal quite horrifically.

    One interesting aspect of the use of NIMH in the film revolves around its name. The rats never spell it out, and it's only spoken of once in the film when the farmer's wife mentions the organization:

    Yes, you know, the National Institute of Mental Health. He was asking if we had noticed anything strange about the rats on the farm...

  • Backlighting Animation Techniques Gave Two Characters’ Eyes A Frightening Glow

    Don Bluth has been a pioneer of animation since his early days at Disney, and there are few who can match his level of expertise. One of the tricks he used in the film involved the use of backlighting to emphasize the creepiness of several characters' eyes.

    The Great Owl and Nicodemus are presented in this manner, and the eerie glow that emanates from their eyes is both terrifying and mesmerizing at the same time. The technique was expensive, and it was seen in several places other than a few characters' eyes, but those are the examples that viewers often remember.

    The technique is achieved by using animated mattes, which are shot with light shining through from the back. Instead of a painted cell, the light shines through a color gel, which creates an intense glowing effect.

  • The Film Added A Supernatural Element That's Not In The Book
    Photo: Robert C. O'Brien/Zena Bernstein / Wikipedia / Fair Use

    The Film Added A Supernatural Element That's Not In The Book

    The book and movie share plenty of similarities, and the main plot is pretty much identical. The movie did take some artistic license with how it presented some of the characters and events, but the real change is in the supernatural elements, none of which were in the novel.

    In the movie, Mrs. Brisby meets the ancient rat, Nicomedus, who tells her of her late husband's connection to the rats and then gives her an amulet called "The Stone." More than simple jewelry, the stone is a magical artifact that grants the wearer power when they are courageous (which is something Mrs. Brisby isn't for much of the movie).

    By the end of the film, just when all hope is lost, she manages to save her children with the power of the amulet, and while many of these events were in the book, they were carried out in natural rather than supernatural ways.