Antonyms for the phrase "knocking around with" would include words like "avoiding," "ignoring," "isolating," or "separating." These antonyms indicate a lack of social interaction, and may suggest a desire for solitude or independence. Alternatively, antonyms could include "networking," "socializing," "mingling," or "collaborating," indicating a desire to connect with others and build relationships. It ultimately depends on the context of the phrase "knocking around with," and whether it represents positive or negative social behavior. Regardless, there are a variety of antonyms that can be used to illustrate different types of social behavior and interaction.