How does Opal know that Winn-Dixie does not like to be left alone?

Opal knows that Winn-Dixie does not like to be left alone because he displays anxious behavior when she prepares to leave him, such as whining and following her around the house. Additionally, his reaction to being left alone, like how he causes a commotion at the store when she leaves him outside, further confirms his dislike for solitude. These behaviors indicate his strong attachment to Opal and his discomfort with being separated from her.