Rich Mice is a Treasure Chest segment in the Richie Rich cartoon series. It first aired 10 October 1981 on the fifth episode in the second season of the series, as part of The Richie Rich/Scooby-Doo Show, and was rebroadcast 4 December 1982 during the third season on, as part of Episode 11 of The Pac-Man/Little Rascals/Richie Rich Show.
Richie is examining a rare nickel, but suddenly drops it and ends up in a hole through the wall. Using a special spray supposedly invented by Professor Keenbean, Richie and Dollar voluntarily shrink themselves to a smaller size to try to retrieve the coin, but encounters a family of wealthy, talking mice who tries to hoard the coin, and is used as a replacement wheel on their wind-up car. Richie offers an incentive on the condition that the mice surrender the coin to him. Richie reclaims the coin, and escapes from the mice who chase Richie in their car.
Richie and Dollar are now back to normal size, and Richie mentioned the spray is useful and said they should use it again someday. After a bad experience, Dollar grabbed the spray, and threw it out a window, only to end up coming into contact with a Rich Refuse worker whose truck had just pulled into the driveway, shrinking them, causing the worker to get angry. Dollar quickly closed the curtain, and walked away from the window on his hind feet feeling quite embarrassed, as if he was about to face consequences.
- This is the only time in the series that Richie's shrinking and was not caused by a villain.