Why does Avery want to capture Charlotte in Charlotte's Web?

In "Charlotte's Web," Avery wants to capture Charlotte because he sees her as a potential threat to his plan to catch Wilbur, the pig. He believes that capturing the spider will help him gain an advantage in his efforts to win a prize at the county fair. Avery's actions reflect his youthful impulsiveness and desire to assert control over the situation, unaware of the deeper bond between Charlotte and Wilbur. Ultimately, his motivations highlight the themes of innocence and misunderstanding in the story.