Answer:
He destroyed the mouse's winter shelter
Explanation:
In this story, the speaker apologizes for having destroyed the mouse's winter shelter and having now given it cause to fear its fellow man.
The word <em>wishing </em>is used as a participle in this case. Although gerunds and participles look the same, they are used in different senses - gerunds generally denote nouns, whereas participles have more of an adverbial meaning.
