Follow TV Tropes


Literature / Mrs. Frisby and the Rats of NIMH

Go To

"You must go, Mrs. Frisby, to the rats under the rosebush. They are not, I think, like other rats."
The Owl

This page is about the book Mrs. Frisby and the Rats of NIMH. If you are looking for the article about the animated film, see The Secret of NIMH.

A 1971 novel by Robert C. O'Brien about lab rats that gained human intelligence through a series of top secret government experiments.

The protagonist of the story, Mrs. Frisby, is a fairly intelligent, but otherwise ordinary field mouse. Mrs. Frisby seeks a way to keep her sick son, Timothy, alive during the spring plowing. He is too weak to move to their summer home without risking his death, but staying would mean certain death because their winter home lies directly in the path of the farmer's tractor. In order to ensure her son's survival, Mrs. Frisby seeks the help of the elusive uplifted rats of NIMH (National Institute of Mental Health).

The first and last third of the book are told from the (third person limited) perspective of Mrs. Frisby while the middle third is a long flashback, narrated by Nicodemus. The sections of the book focusing on Mrs. Frisby are concrete and down-to-earth: the humble realities of a humble creature trying to save her family. The animals in that section are anthropomorphized quite a bit and all of them are rather intelligent, even without being uplifted. Nicodemus's chapters are quite different in tone, almost to the point of Mood Whiplash. His chapters deal with their escape from NIMH and his intellectual journey afterward, and the animals in this chapter are less human than those of Mrs. Frisby's. If read separately you would be forgiven for thinking it was from a different story. The NIMH chapters examine animal intelligence, the psychological differences and similarities between humans and rats, The Scientific Method, and the philosophical ramifications of stealing.

It was written in 1971 and made into a very loosely adapted animated feature-length film called The Secret of NIMH by celebrated director Don Bluth. After O'Brien's death, there were a couple of semi-official sequels written by his daughter, Jane Leslie Conly — Racso and the Rats of NIMH (1986) and R-T, Margaret, and the Rats of NIMH (1990).


  • Air-Vent Passageway: The rats use the air vents to escape NIMH. It's portrayed realistically with the rats spending over a week exploring the vents with a spool of thread before they know the way out well enough to escape. Rats of course, are also much smaller, lighter and make less noise than humans, which makes the trope more plausible in that respect as well. Even things like the fans used to provide air movement are taken into account. They're not giant and looming, but the strong wind they provide actually blows away lighter animals into other passages and ducts where they can't be reached or even found. The mesh on outside of the vent to prevent debris from entering the ducts provides a significant obstacle, as well, as the rats have much trouble removing it from the inside and are only able to pry open a small enough hole for mice to fit through.
  • Amplified Animal Aptitude: The relative intelligence of ordinary animals presented here is an interesting thought. The non-uplifted animals aren't as dumb as the scientists at NIMH would have thought, though the NIMH experiments did help the rats grow even more. As an example, Mrs Frisby may understand concepts of marriage, moving or eating something to make you better, but she doesn't know how to actually make the medicine, work a cage door or even a light switch—things the uplifted animals show they have learned.
    • It is mentioned Jonathan managed to teach her to read but only through a lot of work, and she still isn't that good at it. Which, however, he learns perfectly as an uplifted NIMH subject.
  • Animal Talk: The animals can talk to each other, but can't talk to humans.
  • Anthropomorphic Shift: The chapters in the original book involving Mrs. Frisby have animals that are more anthropomorphic than the ones involving the rats of NIMH. Ordinary rodents are seen using tools and can understand some very human concepts without much difficulty. It's possible that this is because the NIMH chapters are from the rats' perspective while the rest are from relatively normal Mrs. Frisby's perspective. One would expect Mrs. Frisby to see her fellow non-uplifted animals as being fairly bright.
  • Arcadia: What the rats eventually want to live in.
  • Artistic License – Linguistics: Mrs. Frisby and her children are referred to as "field mice". The term "field mouse" actually refers to the eastern meadow vole, which is not a mouse at all. It would be impossible for an escaped laboratory mouse to breed with one. The story never portrays her as anything other than a mouse, and the illustrations of her clearly show a mouse and not a vole, so the author probably just made a mistake in terminology.
  • Buried Treasure: By field mouse standards, the stash of food Mrs. Frisby finds is this.
  • Bus Crash: A splinter group of rats, which includes Jenner, is killed by an accident at a hardware store. Said group departed even before the main storyline; the event is only described by some tertiary characters and is never shown.
  • Carnivore Confusion:
    • The owl declines to eat Mrs. Frisby, and even gives her advice on how to save her son.
    • Mrs. Frisby's neighbor and apparent friend is a shrew, and shrews also eat mice. So do crows.
  • Cats Are Mean: Dragon. A recurring saying among the animals is, "We all help one another against the cat.". Even the owl goes by this.
  • Clever Crows: Jeremy is a very useful and helpful crow despite his young and inexperienced nature, He helps Mrs. Frisby when she needs help, Unlike his Animated Version, In the book, Jeremy is shown as someone more smart.
  • Didn't Think This Through: Let's capture some rats and make them hyper intelligent. Then we should make cages that they can physically open and then put written instructions on how to open the cages on them. And heck, while we're at it we should also teach them how to read.
  • Elaborate Underground Base: The rats have one of these, complete with electricity, machinery and running water stolen from the humans that live nearby.
  • Even Evil Has Standards: The old owl who lives deep in the forest preys on rodents, and could most likely make short work of a cat, but he is still of the opinion that Dragon is something that animals should help each other out against (although he might be choosing to help small animals avoid the cat so that he can eat them later, once he's actually hungry...) The owl also has a personal sense of hospitality that prevents him from harming visitors in his home, no matter how edible.
  • Escaped from the Lab: The uplifted rats and mice, naturally, which kickstarts the whole story.
  • Exact Eavesdropping: While held captive by the humans, Mrs. Frisby just happens to overhear a conversation about 'mechanized rats' killed trying to steal a motor, and how some scientist type is interested in coming to see the farm's rat colony.
  • Eye Scream: Nicodemus lost his eye some time in the past. What exactly happened is never explained.
  • Eyepatch of Power: Nicodemus wears one; subverted by it not being a scar of combat, but of a mundane injury—one that, by his own admission, significantly impaired the eyesight in his "good" eye as well as rendering the other eye completely blind.
  • Foreshadowing: It's mentioned that while Jonathan did teach Mrs. Frisby about reading, she struggles with it even in the present day. Meanwhile, their kids easily took to the skill. This hints to Jonathan's past as an experimented lab mouse prior to meeting his far more normal mate.
  • Genetic Engineering Is the New Nuke: The Rats and mice at NIMH were given a cocktail of unspecified DNA and steroids which increased their learning capacity and speed by a factor of 1000% and almost completely halted their aging. Quite prescient and unusual for a work set dab smack in the middle of the Cold War.
  • Gone Horribly Right: The result of the experiment on the rats and mice of NIMH — the rats became strong and smart enough to revolt.
  • Hidden Elf Village: The rats' colony in Thorn Valley is fully intended to be this in order to avoid capture and/or extermination while also serving as the basis for the future uplifted rat civilization.
  • House Squatting: The titular rats take shelter in a luxurious mansion called the Boniface Estate not long after escaping from NIMH. The owners of the mansion are wealthy newlyweds who went on a trip around the world, leaving the estate unoccupied. The rats take caution not to be discovered by the groundskeeper who maintains the lawn and garden; they hide during his visits, clean the house, and haul their garbage far off into the nearby woods to avoid detection.
  • Humans Are the Real Monsters: Rats see humans like this in a way, because of their vehement and perhaps irrational hatred of rats, and sticking them with needles and shocking them through their feet. Over time though they take on a more mature outlook of humans being somewhat foolish with how they use technology while also recognizing that they themselves have fallen into some of the same pitfalls.
  • Immortality Begins at Twenty: The offspring of the laboratory-altered rats of NIMH all age at a normal rate for a rat. If they do exhibit the longevity of their parents, it will be the kind that begins at sexual maturity. On the other hand and depending on how you interpret the text, mice exhibit the extended lifespan (perhaps to a lesser extent) from day one. Mrs. Frisby's children are still children at over a year old, a fact that goes unremarked by their mother.
  • Inexplicable Language Fluency: The animals can understand humans and each other, but can't talk to humans. This leads to a bit of Fridge Logic as to where exactly all these animals picked up English (justified for the rats, as they were taught it in the lab, but not for any of the others), and whether they can understand other human languages automatically as well.
  • Informed Flaw: The unintelligence of non-NIMH experimented animals for one.
  • Intellectual Animal: The entire cast.
  • Kansas City Shuffle: When the NIMH agents come to bulldoze the rosebush on the Fitzgibbon farm, the rats don't defend, fortify or fight for their nest. The rats allow NIMH to destroy their base, but they dig an extra tunnel leading into the forest and use it to evacuate all the rats before NIMH arrives. They then task a handful of rats to run back into the nest through the tunnel, escape through the main entrance, and then run back into the tunnel and out again. This leads the exterminators to believe that they have killed or at least scattered a large number of rats, even though they only saw the same six or seven over and over again. On top of this, the rats destroyed their Elaborate Underground Base before they evacuated, so that it resembled an ordinary rat's nest. The net outcome was that even though the rats lost their former home, it caused NIMH to mistakenly believe they had taken care of the rat problem and that the rat escapees weren't very intelligent to begin with.
  • Lamarck Was Right: Justified. The book is actually very good about this. The injections given to the rodents at NIMH to enhance intelligence altered their DNA, and thus the Uplifted Animal trait was passed on to the next generation. The injection to increase lifespan was steroid based, and therefore the rats are uncertain if the effects will be inherited. If they are indeed, then it's a case of Immortality Begins at Twenty for the younger generation because they have up until that point at least grown up at a normal rate of aging.
  • Life Imitates Art: While NIMH has long since stopped experimenting on rats and mice since the book was written, other institutes have continued with the work up to and including increasing the intelligence of rats via gene-editing and prolonging their lifespan via blood transfusion.
  • Make It Look Like an Accident: Non-lethal version — when the rats free Mrs. Frisby from the birdcage, they loosen the door hinges to make it look like she pushed her way out on her own (rather than open the lock directly, which she would never be able to do).
  • Malignant Plot Tumor: The B plot giving the backstory of the rats of NIMH, which is easily the best-written and most fascinating part of the book.
  • Married Animals: Mrs. Frisby is a normal-enough mouse living in a Mouse World. She was married, but is now a widow.
  • Mayfly–December Romance: Subverted. The experimental treatment given to Jonathan Frisby greatly increased his lifespan, and potentially those of his offspring as well. He would have outlived his wife by quite a number of years, had he not been killed by Dragon the cat before the start of the story.
  • Mohs Scale Of Science Fiction Hardness: Between 5 and 6 since real-life science has caught up to the book insofar as genetic and biochemical experiments on rodents are now all but standard. Super-intelligent and immortal rodents are however still some ways away though.
  • Most Writers Are Human: The anthropomorphic qualities of the rats of NIMH can be excused due to their greater intelligence and time spent with humans, but even ordinary animals tend to act a lot like people. Mrs. Frisby occasionally mentions marriage and the proper age to marry as if they applied to her, and other rodents in general. The shrew even refers to "the summer of sixty-five", as if animals could recognize specific years.
  • Mouse World: The story centers primarily around mice and rats, so naturally.
  • Mr. Exposition: Nicodemus.
  • Names to Run Away from Really Fast: Dragon, the cat, if you're a mouse.
  • No Control Group: Averted.
  • Obfuscating Stupidity: The rats of NIMH must exhibit this and pretend to be ordinary rats at all times, lest their intelligence lead to discovery and recapture. When moving out of their Elaborate Underground Base, they go to great pains to disguise it as an ordinary rat's nest. They move out all the machinery, destroy all the fancy architecture and fill the whole base with garbage. This was a rush job, and given enough time they would have even destroyed the machinery. In another instance Justin declines to release Mrs. Frisby from a birdcage the conventional way. Instead he opts to disguise her escape as a flaw of the cage rather than opening it deliberately.
  • The Owl-Knowing One: The Owl tells Mrs. Frisby to get help from the rats. He can also envision his own death. When Mrs. Frisby asks why he doesn't just fly away and escape his failing home, he explains that it's all he's ever known, and "When this tree falls I shall fall with it."
  • Precocious Crush: Mrs. Frisby’s daughter Isabella's crush on Justin.
  • Resourceful Rodent: The story is about a group of lab rats that gained human intelligence through a series of top secret government experiments.
  • Rodents of Unusual Size: While the rats of NIMH are nowhere near enormous, they are much bigger than ordinary rats and in fact Mrs. Frisby describes the rat Brutus as being close in size to a tomcat.
  • Sacred Hospitality: The Owl eats mice all the time, but when Mrs. Frisby comes to his home to ask his advice he treats her as a guest and does her no harm.
  • Sequel Hook: Martin pledges to visit the valley where the rats end up settling one day, possibly with the help of Jeremy the crow. Sadly this was unable to be realized by the original author because of his untimely death.
  • The Scientific Method: Shown accurately in the first book. They even use a control group! (But it's not double blind.)
  • Shouldn't You Stop Stealing?: Nicodemus and the vast majority of rats recognize that stealing electricity and such is highly conspicuous and will only get more conspicuous as their population increases. They've even discovered a way to live without having to hijack resources from humans, but it would be harder and less comfortable at first. A dissenting group doesn't fear the repercussions and would rather continue stealing.
  • Shown Their Work: The section narrated by Nicodemus at least. It's very detailed and accurate about The Scientific Method, the inherited effects of the experiments and the psychology of rats.
  • Somewhere, a Mammalogist Is Crying: The NIMH scientists use an apparent opening to the outside world as their rat-training "bait" of choice, and the not-yet-uplifted rats frantically rush towards it when they explore the experimental maze. Real rats are cautious animals that far prefer the shelter and dimness of a tunnel to sunlit open space, where birds of prey or other predators could snatch them up: if anything, they should retreat from such an exit.
  • Super Serum: Whatever the combination of DNA and steroids the rats at NIMH received was. And it worked beyond the researchers' wildest dreams.
  • Terminally Dependent Society: The rats in relation to human technology and foodstuffs. The Plan ultimately aims to make them a self-sustainable civilization.
  • Truth in Television: Part of the reason the section about NIMH is so realistic is because the section was inspired an actual series of experiments done on rodents at NIMH, which is even an actual place
  • Uplifted Animal: The rats of NIMH, Jonathan Frisby and Mr. Ages are all as intelligent as or even more intelligent than humans.
  • What Happened to the Mouse?: The six mice who were blown down various air vents at NIMH are never seen or mentioned again.
  • What Measure Is A Nonhuman: Nicodemus discusses this issue and postulates that human dependency and the lack of tool use are the reasons rats have stagnated in terms of intelligence and civilization. He theorizes that perpetual stealing from humans would just make life too easy and put rats back into a rut where they don't progress at all and live in total dependency on humans.
  • Where the Hell Is Springfield?: Since NIMH is a real place, the story likely takes place on the east coast of the United States somewhere around Washington, with the oft-mentioned mountains likely being the Appalachians. There even exists a real-life Thorn Mountain in New Hampshire.
  • Writers Cannot Do Math: It's not clear if this is an error on the writer's part or on the character's, but Mrs. Frisby noticed that Jeremy was a young crow, only about a year old, but she doesn't notice that her children are over a year old and are still children.