Toto's persistent troublemaking, despite the narrator's family's kindness, stems from his inherent character. He possesses a natural inclination towards mischief, driven by curiosity and a lack of understanding of the consequences of his actions. While the family's affection provides a comfortable environment, it doesn't fundamentally alter Toto's impulsive and playful nature, leading to continued disruptions and chaotic situations. His behavior highlights the difference between providing care and changing deeply ingrained personality traits.