The mice make cameo appearances in the comic strip. They are often portrayed as living their own social lives in their mouse holes.
Although Jon Arbuckle wants Garfield to get rid of the mice, this rarely happens. This is either because Garfield is too lazy to chase them, considers the act of eating them to be abhorrent or actually even befriended the mice living in his house. Jon always blames Garfield if he sees any mice or holes in the wall, such as one time, there were so many holes on the wall that it was extremely easily-recognizable. On at least four occasions, the mice have been given names: Squeak appeared in the mid-1980s, Tommy in 2009, Stretch in 1983 and Herman Vermin in the late 1990s.
There is also one mouse named Stretch (not to be confused with Garfield's rubber chicken), who only appeared in one strip. In the September 9, 2004 strip Garfield was seen celebrating one of the mice´s birthday. They often annoy and mock Garfield; on one occasion three mice dove into Garfield's mouth and jumped back out repeatedly in succession, because Garfield was too lazy to attack them.
On the January 15, 2006 strip, Garfield actually considers the idea of eating mice, explaining that, "If I ate mice, I wouldn't have to wait around for Jon to feed me." Squeak puts him off the idea by pointing out the appearance of the various mice in the house, all of which are ugly enough to make the cat lose his appetite.
Despite the general peace between the mice and Garfield, they have pressed their luck with him with an unflattering song about him and on one occasion using him for a bounce house. They once voted to decide on letting Garfield stay in the house. When Jon issued an ultimatum that either the mice go or he goes, they proceeded to move Jon's suitcase down the stairs.
- Hitting Garfield with a golf ball.
- Using part of Jon's pajamas as its own.
- Building a bay window over its entry hole.
- Writing "HERMAN STINKS!" on the front door.
- Writing "CATS STINK" on Garfield's arm.
- Sleeping on Jon's bed with Garfield.
- Running up Mrs. Feeny's leg (Garfield paid a mouse to do so).
- Using holes cut from one of Jon's bed sheets as makeshift togas.
- Using Garfield's blanket as a makeshift slide show screen.
- Using Garfield's belly as a makeshift mountain top.
- Using Garfield as a makeshift bed.
- Showing Jon its Mouse Of The Year award.
- Eating Garfield's food behind his back.
- Setting up Christmas decorations above its mouse hole.
- Declaring the house property of the Empire of Mice.
- Using part of a Christmas tree as its own Christmas tree.
- Using a slipper, a button, and two spools of thread as a makeshift car.
- Giving Garfield a slice of pie.
- Teasing Garfield's tail with a comb.
- Becoming an interpreter for Garfield.
- Giving Garfield a birthday card.
- Watching television with Garfield.
- Playing golf with Garfield.
- Building mouse-like condos.
- Hiding inside Garfield's coffee.
- Sharing a piece of cheese with Garfield.
- Placing a "NO LOITERING" sign on the wall.
- Dancing with Garfield, Odie, Jon, and Liz.
- Winning an arm-wrestling match against Garfield.
- Giving Garfield advice on what to say by whispering in his ear (this has happened more than once).
- Running out of a cat food box when Jon poured from it.
- Converting a tree into a mouse-like tourist attraction.
- Telling Garfield that 4,732 mice live in a hole in the wall.
- Setting up a mouse hole underneath the living room chair.
- Asking Garfield to get an ice cream scoop and a melon baller.
- Distracting Garfield with various foods while being chased by him.
- Stealing ice cream cones from the freezer via a mouse hole and ladder.
- Setting up various mouse-sized furnishings around the house.
- Inviting Garfield and Odie to a mouse-like wedding.
- Using one of Jon's contact lenses as a salad bowl.
- Carving a hole in a wall; this caused the wall to fall on Garfield.
- Playing volleyball in a birdbath; two birds used a mouse hole in the house as well.
- Using a robot vacuum that Jon bought; Garfield referred to it as the "mouse shuttle".
- Garfield chases a mouse as a rehearsal, which fails to impress Jon.
- Garfield plays tag with a mouse, which only slightly impresses Jon.
- Garfield ties a key to a mouse's back, and Jon mistakes it for a toy mouse.
- Garfield gives a group of seven mice a giant piece of cheese, which they all enjoy.
- Odie uses his tongue to bring a mouse to Garfield, which impresses him.
- When Jon mistakes a toy mouse for a real one, he drops it and falls to the floor.
- When two mice spot a mouse trap between their hole and Garfield's bed, they declare war on it and summon an army of mouse-like soldiers.
- Two mice go on vacation for a week; this causes Jon to assume that Garfield kicked all the mice out of the house and congratulates him for it.
- Jon disguises himself as a mouse; this prompts Garfield to take a picture of him with four other mice.
- Attempting to bathe in a coffee pitcher that Garfield poured from.
- Attempting to use Garfield's water bowl as a swimming pool.
- Attempting to intercept a piece of cheese before Garfield.
- Calling Garfield fat; this prompted Garfield to crush the mouse with his stomach.
- A mouse attempts to make a hole bigger with a mouse-sized chainsaw, which fails to impress Garfield.
- A mouse is kicked out of its mouse hole by its wife after eating a garlic bulb.
- Jon attempts to set up a mouse trap, only to end up caught in it.
- Jon attempts to seal off a mouse hole; this causes four mice to sleep in Garfield's bed with him.
- Jon gives Garfield a rubber mouse to play with, which Garfield rejects. There are also instances where Jon gives Garfield a toy mouse, with similar results. Both have happened multiple times.
- Garfield rescues a mouse from a vacuum cleaner, only to have the machine suck it back in.
- Garfield reads a story of how a cheese fairy was eaten by a cat; this only scares the mice who heard the story.
- Jon gives Garfield a piece of cheese in an attempt to lure the mice out of a mouse hole; Garfield eats the cheese instead.
- Jon orders Garfield to kill and eat a mouse that was walking on the table, which Garfield refuses to do.
- They have appeared 401 times in the comics, the 5th most.
- Garfield once was surprised because there was only 4,076 of them.
- Garfield does not like toy mice or rubber mice.
- Jon does not like the fact that Garfield never actually chases them, as Garfield does not like chasing mice.
- Jon once showed Garfield what chasing mice is supposed to look like.
- In Here Comes Garfield, Jon suggests chasing mice as a way for Garfield to provide for himself. Garfield turns down the idea due to bad breath.