Catching/Stopping the Mice from getting into house
Patch up the hole to stop more mice from getting in.
Put traps (or a cat - personally, I'd prefer traps) in the house to catch the ones that are there.
So long as they can find food (and mice are really good at finding food), it's likely that the ones that are already inside will reproduce, thus rendering the &quot;wait until they all die&quot; option somewhat ineffective. Of course, if you happen to have all males or all females inside, that combination cannot reproduce, but it's probably not worth taking the chance.