The cartoon mouse's refuge: a neat arch-shaped hole cut into a wall at the floor, sometimes with a door.
The holes Real Life mice gnaw through walls are of course not so perfectly shaped as these, though the sapient inhabitants of fictional Mouse Worlds might be capable of engineering them. However, the existence of neat arch-shaped holes in baseboards is Truth in Television, as these were often cut for plumbing installations (especially heating pipes) and are often wide enough that mice can and do crawl through them.
- Pleasant Goat and Big Big Wolf: A little hole in the wall with some mice living in it is seen in Wolf Castle at least once.
- A trademark schtick of Garfield strips. Sometimes this even extends to windows with pots of flowers under them, mailboxes, welcome mats, etc.
- Again, not mice, but The Littles use this trope.
- Episode 20 of Monty Python's Flying Circus has a ratcatcher looking for rat holes in a house. The first one he finds is a Mouse Hole, complete with fake mice on a string. The mice aren't the problem for the homeowners, though- the real problem is a killer sheep armed with a gun living in a much larger Sheep Hole who shoots the ratcatcher when he steps inside.
- There is a mouse hole in Mr. Bean's apartment. In the Christmas Episode, he puts a mousetrap in front with a present on it.
- Pee-Wee Herman had a mouse hole in his playhouse. Except it didn't contain mice... instead, one would find a family of Claymation dinosaurs.
- In Alien Squatter, these can be found scattered all over the map. The game doesn't go into any detail about the holes but they do fit in to the derelict theme of the game world.
- The Legend of Zelda:
- While they're not mice, the Minish in The Legend of Zelda: The Minish Cap have several small holes that look like this. They do, indeed, lead to the Minish's Mouse World.
- Also, in The Legend of Zelda: The Wind Waker, some areas have little holes that constantly spawn evil mice, which try their best to stay off your camera and tackle you from where you can't see them, stealing your rupees. Sometimes they even carry bombs. Either way, it's possible to negotiate with them by throwing some bait near their hole.
- In Luigi's Mansion, these are all over the place. Some release golden mice, worth major dollars. Luigi can enter most or all with a special device, usually yielding more treasure. Or ghosts. Often both.
- One of the first puzzles of Sam & Max Hit the Road requires you to grab a stash of cash from one of these.
- One puzzle in The Neverhood involves getting a mouse to a wedge of Cartoon Cheese via a wall of mouseholes. Your job was to figure out which holes the mouse would stop at.
- Glider PRO has a stock mouse hole that can appear in any old room.
- Undertale has several of them, complete with Cartoon Cheese in front of them, the problem being that they are impossible to get (they are respectively stuck to the table, crystallised, and kept in a computerised safe, plus a plate of cold spaghetti with an unplugged microwave somewhere in the middle). Examining the holes will result in a squeak being heard. In the Golden Ending Playable Epilogue all the cheeses are gone, presumably eaten by the mice. (The mouse with the spaghetti tries to eat it, but it's so rock-hard it gives up partway through.)
"Knowing the mouse might one day leave its hole and get the cheese... It fills you with determination."
- Sid And Als Incredible Toons substitutes mine tunnels for the standard cartoon mouse holes; Sid E. Mouse even puts a mining helmet before entering them, though Al can also squeeze through them in pursuit.
- Tom and Jerry, as in the picture above.
- Early Mickey Mouse cartoons didn't show his house, but early comic strips and children's books did. It had a round, obviously mousehole-like front entrance despite Mickey's large, non-mouselike size. In 1931, Mickey's house began to be shown in the cartoons and had a normal front door there, after which the ancillary material was retconned to match.
- The "Pixie & Dixie and Mr. Jinks" shorts on The Huckleberry Hound Show
- Looney Tunes:
- The cartoons featuring Speedy Gonzales and, before that, Babbit and Ratstello.
- Sniffles lived in a mouse hole in some shorts as well, even earlier.
- Mostly averted in Walt Disney's Cinderella, but there is one.
- My Little Pony: Friendship Is Magic: Fluttershy may have purposefully installed a mouse hole in her cottage to shelter mice.
- Invoked in Tex Avery's King-Size Canary, when the jumbo-sized cat and mouse do this with a train tunnel (@ 7:02).
- You might notice the classic arch-shaped mouse holes in the skirting boards in the background on The Simpsons.
- In Futurama, the vermin live in holes like this. The vermin in this case being owls.
- Motormouse lives in one in the Motormouse and Autocat segments of The Cattanooga Cats,
- Winslow lives in one of these in CatDog, complete with a door.
- The Animated Adaptation of Spencer Johnson's Who Moved My Cheese depicts the mice's houses as arched Quonset huts, in contrast to the more squared-off houses of the littlepeople.
- The Simpsons:
- Episode How Munched is that Birdie in the Window?: In the intro, when the Simpsons entered their living room, Prof. Frink shrank them and they ran into the hole to escape the cat.
- An earlier gag had the family sitting down on the couch, only for the camera to zoom into a hole to show a mouse version of the family sitting on their couch.
- In the Ed, Edd n Eddy episode "Once Upon an Ed" in the outside wall of Jonny 2x4's house to escape the Kankers. Ed crams his two friends inside and forces himself in after them but being his story the reasons why they do it is a warped version of how they got into Jonny's wall.
- Can be seen in the kitchen in Courage the Cowardly Dog.