That meant the plane couldn't then set off for its next destination, New York in America before its final destination of Mexico.
The people working for Swiss International Air Lines were worried that the mouse would chew through important cables.
Sad ending to the tale
Unfortunately, this story doesn't have a happy ending.
Rather than try and catch the mouse with a cat or using cheese, the airline workers pumped carbon dioxide gas into the plane to kill it, although they did say this was the most painless way of doing it.