Just two, how did they get in there anyway?
I don't know... I broke the lightbulb after I threw the first one.
Zero. They don't exist.
Just one... But it takes 4 episodes and Krillin dies...
None. Mice can't change light-bulbs as they are mere rodents without the physical or mental ability to do so. Not to mention it's much safer for them to pilfer food in the dark.
An unidentified flying omelet!
Clive, usually.