A Mouse in the House is the 32nd cartoon of Tom and Jerry that was made in 1947.
A fed up Mammy Two Shoes threatens to rid of one of her lazy cats when she's tired of dealing with all the mice problems. However, both cats as well as Jerry are out of the house in the ending.
Mammy Two Shoes stumbles upon the kitchen which has been ransacked by Jerry (who has had a jam session in the bread box, raided the refrigerator, and took bites out of Mammy's chocolate cake), and goes on a tirade against the residents of the house: Tom and Butch. She ventures into the living room, where she finds them lazing around and drinking cream. Sarcastically pleased that the cats are satisfied, she yells "'cause I ain't! There's a mouse in the house, and there's two cats. But there's only gonna be one cat in this house in the morning -- and that's the cat that catches that mouse. Now get going!"
The two cats frantically begin their search for the mouse, and are unsuspectingly aided by Jerry, before realising the mouse was under their noses the whole time. They scramble to catch Jerry, but instead become entangled. On only one of their four feet, they tiptoe across the floor, until the mouse motions at them to stop, at which point, he hits that foot with a fireplace log. This was Butch's left foot; he screams, jumping up and down, clutching Tom's left foot and eventually noticing he's got the wrong foot. He lets go of Tom's foot and grabs his foot, screaming. The chase continues as Tom and Butch both grab Jerry together and decide to have a duel using a pair of guns they find lying around. Tom turns around as they pace across the room and tries to shoot Butch, but instead he finds out it's a "novelty gun", which whacks Butch on the nose. Butch, assuming he has a real gun, chases after Tom, until Tom sees the brand name on it (which is the same as the other one) and assumes it is another novelty gun. He chuckles at this. Tom threatens Butch to shoot him. The gun goes off, and Tom has barely dodged the bullet, but it comes out of the wall, rolls down Tom's head, and hits Tom's nose.
The chase continues into the kitchen, where Jerry jumps into a gas oven. Tom and Butch slam the door and turn on the gas as Jerry sneaks out, lights a match and drops it in the oven. Tom and Butch open the oven door and the oven explodes on them.
Jerry and the cats move into the living room, and the two cats hide. The mouse looks both ways and slowly walks out, but is caught by both cats. Jerry squeezes out of their grip, but is then grabbed by Butch. Tom grabs his opponent's tail as he flees, and stops Butch, but meets his ire as well. Tom bops Butch on the head, and Butch slips the mouse into a box with a sliding cover before fighting it out themselves. Jerry escapes from the box and rings a boxing gong, ending the fight, and cleans up and coaches both cats to hit each other. Jerry rings the gong and both cats end up punching each other, as planned. They realize they've been tricked and glance towards Jerry, who is mocking the fight. Both of them pull up on either side of the mouse.
Eventually seeing he is trapped between the two, the mouse chooses Butch via Eeny Meeny Mine Mo, taunts Tom, and sits down in Butch's hand. Butch snaps his fingers in victory, and Tom slumps down and walks away, then hides behind a curtain. Butch is reveling in his victory until Tom reaches out and grabs Jerry directly out of the other cat's hand. Butch turns the corner and opens the curtain to find only Tom, who pretends to not know where the mouse is. Then, Jerry (underneath Tom) lifts up the cat and carries him around to reveal himself. Tom simply continues with the charade, and Butch grabs Tom, revealing the mouse underneath, who soon realizes Tom is missing. Butch stuffs Tom into the trash can and chases Jerry. Annoyed, Tom runs into the kitchen, dressing himself in Mammy's clothing in order to trick Butch. Butch enters the kitchen, with Jerry clenched in his fist, and offers him to Tom, thinking that he is Mammy. Tom wallops Butch over the head with a frying pan, dashes out of his disguise and runs off with Jerry. Butch regains consciousness and runs into the living room, wearing Mammy's clothing, while pretending to arrange the bookshelves. Tom walks into the living room, with Jerry in his fist, and offers him to Butch, thinking that he is Mammy. Butch wallops Tom over the head with a chimney shovel, dashes out of his disguise and runs off with Jerry, until he runs straight into an ironing board and knocks himself out. Jerry escapes from Butch's clutches and runs off. Both cats pick up the weapons used against them and chase after the mouse.
Just then, we see Mammy walking down the stairs. She says "I think I'd better go peek in on them two cats." Tom approaches from one room, sees Mammy, and thinking that he's seen Butch in disguise, hides behind the stairs. Then Butch approaches from another room, also sees Mammy, and again thinking that he's seen Tom in disguise, hides on the other side of the stairs. As Mammy peeks through a door, the two cats hit her on the bottom repeatedly with their weapons, both thinking that Mammy is the other cat. Mammy screams in pain and the cats look at each other, and move her pant leg to reveal who they have attacked. They flee, but Mammy angrily grabs them by their tails ("Hold on there, you crazy cats!"), attacks and throws them out of the house. Jerry, thinking he got the last laugh, watches and walks back into the house, but is met with Mammy tapping her foot. Resigned, the mouse slowly walks back out the door, and shuts it as he dashes away.
- This is one of only three cartoons where Butch is shown as a house cat. The others are Blue Cat Blues and Scat Cats.
- This is the first and possibly the only short where both Tom and Butch are house cats in the same house.
- This is one of the four cartoons in which Mammy Two Shoes' head is shown. The others are Part-Time Pal, Mouse Cleaning, and Saturday Evening Puss.
- The scene where Tom and Butch show up in blackface after the smoke clears from an explosion was cut in most re-runs of the episode.
- This is one of the 19 shorts in which Tom and Jerry both lose in the end. The other cartoons are Fraidy Cat, Baby Puss, The Truce Hurts, Polka-Dot Puss, The Little Orphan, Saturday Evening Puss, Safety Second, The Framed Cat, His Mouse Friday, The Missing Mouse, Baby Butch, Downhearted Duckling, Muscle Beach Tom, Blue Cat Blues, Feedin' the Kiddie, Tot Watchers, Filet Meow, and Advance and Be Mechanized.
- Originally Mammy was voiced by Lillian Randolph. When redubbed she was voiced by Thea Vidale.
- Until Smarty Cat, it was the last cartoon to be animated by Michael Lah.
- This is one of the eight cartoons in which Mammy Two Shoes attacks Tom. The others are The Midnight Snack, Fraidy Cat, Part Time Pal, Saturday Evening Puss, Mouse Cleaning, Nit-Witty Kitty, and Sleepy-Time Tom.
- This is the one of five cartoons in which Tom attacks Mammy Two Shoes. The others are Fraidy Cat, The Lonesome Mouse, Part Time Pal, and Nit-witty Kitty.
- This scored the same number of viewers as The Night Before Christmas.
- This is one of the few shorts where Mammy Two Shoes isn't scared of Jerry.
- This is one of the few shorts where Tom loses with another cat. The others are Sufferin' Cats!, Baby Puss, Tennis Chumps, Saturday Evening Puss, Tom and Jerry in the Hollywood Bowl, Jerry's Cousin, Casanova Cat, Smarty Cat, Muscle Beach Tom, Catty-Cornered, and Cat and Dupli-cat.
- Butch uses Tom's scream when he hurts his foot.
- A Mouse in the House at B98.tv