Similar in many ways to Beneath the Earth, the Mouse World exists in secret on the fringes of human society; the difference is scale. This is an entire class of stories built around tiny protagonists operating just out of sight in the human world. These come in a few flavors, but all share some important common elements. In any case, the lives of the little folk draw eerie parallels to the lives of the big-folk.
In an urban setting, the characters most often act like rats, even when they aren't actual Talking Animals in the 3- to 6-inch range. They live in Mouse Holes using adapted or cobbled-together materials made from human trash with the odd toys and models thrown in usually making it Scavenged Punk.
If they deal with human opponents directly, expect clever trickery, stealth and the odd Colossus Climb or Gulliver Tie-Down. They may become Dinky Drivers to operate human vehicles. In more rural or wilderness setting, the may live in Mushroom Houses. If humans aren't aware of them in the slightest (as in most cases), it's usually because they either have a strong Weirdness Censor, the tiny species is keeping a complex and clever masquerade, they operate a Mobile-Suit Human or two, or they simply regard talking and/or clothed Funny Animals or tiny humanoids as an Unusually Uninteresting Sight. In some cases one lucky human (usually a child) Speaks Fluent Animal and is the only human character in the story aware of the tiny species. In combination with an Incredible Shrinking Man, you can have a Trapped in Another World plot. Other slightly larger animals such as cats and dogs may also play a role in this world, but expect Animal Jingoism to come into play, along with examples of Cats Are Mean.
The trope may have begun with the original Lilliputians, and later Gulliver's time with the Brobdignagian giants, in Gulliver's Travels by Jonathan Swift (although there were a few very small beings in some cultures' version of the Oral Tradition, long before Swift's time). The best-known recent version is probably The Borrowers books and their adaptations to other media.
The Mouse World is almost always a Wainscot Society, more or less literally. ("Wainscot" is wooden panelling on interior walls, and small beings might live behind the wainscot in houses; mice often do in the real world.) However, the Mouse World may not feature a fully-developed society. Hence, this is a Sister Trope and often functionally a Subtrope to that one. Not to be confused with the Disney Theme Parks. If you're looking for little people who don't necessarily live in one of these worlds, head over to Lilliputians.
Sister trope to Knee-High Perspective.
- There is a weirdly humanlike monkey society in The Jungle Book, but they do not act humanlike around any person other than Mowgli. The animals in general only act humanlike toward Mowgli.
- In Incarceron anyone who enters the Prison is shrunk down to fit into it. Said Prison is, in fact, a silver cube set on the Warden's pocketwatch.
- The Far Side loves this trope. There have been cartoons featuring rodents, fish, arthropods and even microbes whose behaviour mirrors (and of course satirises) that of humans.
- The dogs in All Dogs Go to Heaven have a whole culture with gambling casinos and all.
- Gamba: Gamba to Nakama-tachi (Adventures Of Gamba) stars a group of talking mice. The film is also an adaptation of the 1975 anime Ganba no Boken.
- The scene in MouseHunt in which the mouse's room is shown, consisting of a postcard as a poster and a little bed made up of a tin box and cotton balls.
- The young adult Discworld novel The Amazing Maurice And His Educated Rodents: although the sapient rats are an unusual case, not the norm.
- Played quite straight in the novel The Prince Of Darkness, about a Rat-Machiavelli eventually being overthrown by a communist revolution...
- China Miéville's King Rat plays this with gritty realism. Organized rats are real city rats living in the sewers.
- The Tale of Despereaux has one for mice (the Trope Namer), who live in hiding in the main castle, and one for rats, who live in the lightless dungeon. They all have to stay hidden because, after the queen died of a heart attack after a rat fell in her soup, the king essential declared war on the rats, and on the mice by association, forcing them all into hiding.
- The Redwall books started out with a few elements of this, which were later Ret Conned away.
- The most obvious example of this is the horse and human-sized cart Cluny and his horde first show up in. Horses are never seen again in the series. Then there's the stampede of cows through a village, a dog, and an abandoned barn.
- There's also St. Ninian's church, which was burned down in Pearls of Lutra, and a mention of the (human) country of Portugal in the first book.
- Firmin by Sam Savage is a novel about a rat who lives in a bookstore and is a consumer of great literature (literally — he finds it quite tasty).
- The Christopher Churchmouse series of biblically-oriented short stories, written by a Barbra Davoll, is set in a church where mice live much the same lives that humans do in secret, even including attending the preacher's sermons.
- One has to wonder what those mice would think if, in this universe, God made only humans in his image and favours them over other species—including the mice themselves. Probably best not to dwell on it.
- Margery Sharp's The Rescuers series, source material for the two Disney Animated Canon films.
- In the book, House Of Tribes. It shows life entirely from the perspective of rodents. It is a very well done example, that fits this trope to the T.
- Portlandia has a skit about a trio of rats living in Portland voiced by Fred and Carrie.
- Mice and Mystics, an RPG-based board game similar to Descent.
- The Ratatouille ride at Disneyland Paris takes guests through the Mouse World experience, traveling on rat-themed carts under furniture and through spaces between walls.
- Scurry, where the main characters are talking mice who inhabit in a ruined human house and live by scavenging human food — though, as fitting the tone of the (possibly) post-apocalyptic setting, they have very little of the usual comforts of the trope.
- Chip 'n Dale Rescue Rangers, although one not exclusive to rodents. Dogs, cats, arthropods, fish, birds, and pretty much every other sort of animal is an active part of the Mouse World.
- An American Tail, films and series. Theirs comes complete with animal Expys of actual human historical figures, and the mice themselves are essentially metaphors for oppressed minorities.
- The Great Mouse Detective (which was based on a series of books by Eve Titus, Basil of Baker Street). Exaggerated in that while set in London, the mouse version of London is almost exactly the same as the human, without Bamboo Technology. They have clockwork, guns, functioning cabarets and (bizarrely) even Queen Mousetoria, who's an identical mouse version of Queen Victoria. Also, living directly under Sherlock Holmes' house is Basil, a mouse who's an amazingly clear if Disney-fied Expy of Holmes himself.
- The Rescuers and The Rescuers Down Under, two animated Disney features based on the aforementioned series of books by Margery Sharp.
- Cinderella's mouse-friends, though not the center of the story, have significantly adapted the house so they can move about freely inside it.
- The novel Mrs. Frisby and the Rats of NIMH, or The Film of the Book The Secret of NIMH.
- The movie took it far further, though; the mice have tables, chairs, a bed, separate rooms and curtains in the doorways of their home, whereas in the original it was just a two-opening cinderblock.
- The novel (and the later sequels) did state that the Rats of NIMH had made their tunnels surprisingly human-like (and it only got more so, after they moved to the valley, including a statue of one of the rats who died near the end of the first book). Racso even has some of the younger rats figuring out how to make candy. And Mrs. Frisby was married to one of the mice from NIMH. So her husband might have been partial to human-like amenities, and Mrs. Frisby humoured him.
- The computer-animated film Flushed Away has a rat-sized recreation on London made out of junk in the Absurdly Spacious Sewer, with its own Tower Bridge, Picadilly Circus (complete with not-so-big screens) and Big Ben.
- Danger Mouse, although the scale is not kept consistent. Abandoned in The Remake, which is simply a World of Funny Animals.
- Played quite realistically in Ratatouille, where the most Bamboo Technology utilized by the rats is their musical instruments. Other than that, they're quadruped rodents. Remy, who engages in more humanlike behavior like walking on his hind legs and reading, is considered an oddity by the others.
- The rat-adapted kitchen of the bistro at the end of the film expands upon its Mouse World elements, with tiny ladders granting Remy's colony-mates access to high shelves and kitchen appliances arranged so teams of rats can manipulate them.
- Also used, of course, in Video Brinquedo's Mockbuster of this movie, Ratatoing.
- Once Upon a Forest, though it takes place mostly in the wilderness where humans are seen as mythical, frightening and destructive monsters, the Woodland Creatures encounter with 'the yellow dragons', aka construction equipment, as well as other human inventions such as streets and animal traps qualifies it. They also live in houses built into trees.
- Most Tom and Jerry and Tom and Jerry Tales cartoons and episodes.
- Most of Pinky and the Brain is set in a "normal" human world; however, the episode "The Third Mouse" (a parody of The Third Man) is set inexplicably in a 1940's Mouse World.
Brain: Quickly, Pinky! We must return to the past! I must change it all back again!
- The episode "When Mice Ruled the Earth" has Pinky and the Brain trying to create one of these, and succeeding at the end. Unfortunately, all the mice look and act like Pinky.
Pinky: But why, Brain? It'd be easier to rule the world with mice like them!
Brain: Yes, Pinky, but who would want to?
- The Rankin/Bass special 'Twas the Night Before Christmas involves a family of mice living with the family of a human clockmaker. Unusually for the trope, the human is not only aware of his counterpart's existence but actually interacts and works with him.
- One episode of the second season of Flash Gordon establishes that, along with all the other animal-themed races on Mongo, there is a race called the Mouse Folk, who are Exactly What It Says on the Tin.
- Tube Mice a CITV series about mice living beneath a London Underground station, who even have their own MP - Mouse of Parliament.
- Pet supply companies put out a variety of toys for rodents that emulate this trope, such as hamster-sized plastic cars or model huts made of gnaw-friendly materials.
- Professor Schimauski by German artist Walter Moers discovered that his toaster actually worked because there's a little dragon living in it.
- Watership Down, except they live in a rural setting.
- The Mouse and His Child includes both small creatures and non-living things.
- The Wind in the Willows sort of waffles between this and the typical cartoon-animal approach. Sometimes the small animals seem to be the correct size, but sometimes they interact with scaled-down horses and other such non-anthropomorphic animals that really ought to be a lot bigger
- In Redwall, animals live in a medieval sort of world, and they do have tables, ovens, swords, clothing, etc. They don't live in a realistic way, it's very humanlike. However, they do retain characteristics of being animals... moles are good at digging, squirrels are champion climbers, otters are naturals at swimming, some animals are mentioned as being carnivorous (most animals in the series eat only fish and eggs, as far as non-plants go).
- The mock epic Batrachomyomachia makes this Older Than Feudalism: it parodies epics like The Iliad by replacing the heroic figures with warrior mice and frogs, fighting each other complete with miniature armor and weapons.
- Fraggle Rock has a wide range of scales to it, but includes a limited interaction between the little Fraggles and the big "Doc", as well as between Uncle Travelling Matt and the Silly Creatures from Outer Space.
- The world of Crossed Claws certainly looks this way, what with the field of grass that goes up far past the characters heads, and a kind, playful cat wanting her new rabbit friend to meet her caretakers which she can only describe as "tall things". It's actually a straight up fantasy world with its own history, and the "Tall Things" are shapeshifting bug monsters.
- In The Bird Feeder, in general, the birds have their own society, with their own odd technology, customs, calendar, holidays, and such. Played both ways in #21, "Relative Size," as Josh wonders whether ants realize how small they are, and a human wonders whether Josh realizes how small he is.
- The Secret World of Arrietty, Studio Ghibli's film adaptation of The Borrowers, features miniature humanoids living in a small house beneath the floorboards a human house, living by "borrowing" (stealing) small necessities from the humans. One of the older humans who used to live in the house had built a dollhouse for the borrowers to live in, and in the end they leave down a creek in a boat made from a teapot.
- Kabu no Isaki by Hitoshi Ashinano. The story is set in a world where everything except humans is 10 times larger (in linear size), but apparently the Earth surface gravity force is not 10 times stronger. Result: Japan appears huge and sparsely populated, humans are piloting what looks like toy airplanes, landing on fuki (butterbur) leaves and such.
- There is also an old one-shot called Kuma-bachi no Koto ("something about carpenter-bees") by Ashinano in which small humanoid(s) and standard-size people co-exist.
- Busou Shinki. Humans are perfectly aware of the sentient girl-shaped toys equipped with lethal weapons, but it's not regarded as something special. There is a fringe Shinki society that few know of, however.
- Ichigeki Sacchu!! Hoihoi-san is also about little dolls battling but instead of each other, the dolls exterminating the rising plague of vermin that have become immune to all pesticides.
- Hakumei To Mikochi, which follows a gnome-like race that lives secluded in the woods and interacts with animals.
- The Littl' Bits, an anime about a small race of humanoids living in the forest. When imported to the United States the characters were all given themed-names rhyming with "Little bit" in an effort to make it more like The Smurfs.
- The Smurfs, a Belgian comic about a race of tiny blue humanoids that was famously adapted into a much more well-known cartoon series, and then a movie series mainly known for being a Human-Focused Adaptation.
- The Polish film Kingsajz is set in such a world, inhabited by gnomes. The title is a phonetic rendition of "king size", here a normal human's size which can be temporarily achieved through a magic potion.
- Strange Magic: The movie's fairy protagonists are small enough to ride armored squirrels as mounts,
- The Borrowers, one of the more famous examples involving tiny humanoids, focuses on little humanoids that live inside the houses of normal-sized humans and "borrow" their household objects to create Scavenged Punk technology.
- Terry Pratchett's Nac Mac Feegle (aka the Pictsies) in Wee Free Men and other Discworld books, finger-sized blue people who live in human burial mounds. His earlier children's books, The Carpet People and The Bromeliad Trilogy (Truckers, Diggers, and Wings) are a more obvious example.
- Possibly the tiniest example is the Protozoan World of the microscopic people in the short story "Surface Tension". Just barely qualifies as interacting with the macro-scale human world, due to the etched metal documents left behind for them.
- A classic of British fantasy literature, The Little Grey Men, features four gnomes who presumably had a Mouse World culture once, but now are the Last of Their Kind.
- Gnomes is a wonderfully detailed illustration on how six-inch humanoids might survive in the wild. For the most part they live In Harmony with Nature but they do occasionally scavenge things from human beings and their domestic animals. There's also depictions of acorns used as cups and pinecone scales as roof tiles and of how gnomes keep field mice as pets and crickets as watchdogs, and there's a wonderful illustration of a gnome in his garden with flowers and nettles towering over him.
- This is how Pauline Clarke figured the Young Men would handle it in Return of the Twelves. The Young Men were a set of (actual) wooden soldiers owned by Branwell Bronte and his sisters Charlotte, Emily and Anne. Taking off on the Bronte kids' idea that the soldiers would see themselves as normal sized and perceive the kids as giant Arabian Nights-type "Genii", Clarke's idea was that the soldiers came to life and moved around when nobody was looking. She describes them navigating the huge everyday world with intelligence and aplomb.
- Land of the Giants (Inversion: regular humans trapped in a world filled with — guess what — giants.)
- Kabouter Plop, (Plop the Gnome) a popular Belgian children's show created by Studio 100, focuses on four (later six) small gnomes that live inside mushroom houses. It gained a few movies over the years.
- Pikmin from Olimar's point of view, although only on the Distant Planet, where grasses are as tall as trees, trees tower out of sight, many areas closely resemble wrecked human bathrooms and playrooms and the like, and most of the "treasures" he collects are things like bottlecaps, dentures and seashells that seem gigantic next to him. His home world is just right for the dominant race's size.
- LittleBigPlanet's Sackpeople are 8cm tall. This becomes obvious when you compare them to the backgrounds, and some of the real-world objects (e.g. the ruler).
- The World of David the Gnome, a Spanish-animated series about gnomes and their lives in the woods, going up against evil trolls and helping out the forest creatures. David, the title character, is a doctor who helps injured animals.
- The Wisdom of the Gnomes, a Sequel Series to David the Gnome.
- Team Umizoomi , depending on the episode. Mostly a subversion, since the humans interact with the team.
- The 80s Saturday Morning Cartoon The Trollkins which managed to combine The Smurfs with The Dukes of Hazzard. No, seriously.
- Oms (humans trapped in a land of giants) in Fantastic Planet.
- Junkville, the setting of a series of Disney comic books starring Bucky Bug.
- Minuscule: Valley of the Lost Ants, except for the opening scene with humans.
- A Rustle in the Grass by Robin Hawdon is a novel about ants told in a Heroic Fantasy style.
- The City Under the Back Steps by Evelyn Sibley Lampman, in which two children are shrunk down to ant size and have adventures in/with an ant colony.
- The cartoon for Maya the Bee, featuring various insects such as grasshoppers and honeybees living in a meadow.
- A Bug's Life: Interestingly, humans never directly appear, but their existence is obvious through the use of garbage as buildings for the bugs in Bug City and at least a trailer-park with a lantern. Also, a beggar cricket has a tablet that says that a kid pulled his wings off.
- Antz is one of the few ones where an unnamed and unseen boy serves as a minor antagonist. Also, Insectopia is made out of trash and the end-reveal, which isn't much of a reveal thanks to the poster, shows that Z's whole adventure happened in Central Park making it more specific than usual about the human world.
- Mr. Bug Goes to Town, a feature-length Fleischer cartoon. The bugs attempt to co-exist with ahuman couple who have a parallel story, after people accidentally endanger them in a park in Central Park their village is built in. They end up finding their garden as a new home.
- Bee Moviem\,centered around a human-like civilization inside a bee hive.
- The Buzz on Maggie, short-lived Disney show about a teenage fly.
- The Doll People features dolls that take an oath upon being made which allows them to keep their sapience. Oddly, Barbie dolls are not alive, although fictional brands of dolls are.
- Barbies could be alive. For some reason, they mostly choose not to take the oath.
- Plüsch, Power & Plunder is a German game about sapient, living plushies who have to keep up the Masquerade from the "tramplers".
- The tiny stitchpunks of 9 live in a Scavenger Mouse World After the End. Noticing everything they've used for their technology, such as a sextant for a telescope, is a lot of fun.
- Osmosis Jones (technically, body cells are living things, but not in its everyday sense.)