Relational bullying involves socially manipulative behavior (e.g. exclusion, ignoring, gossiping/spreading rumors, teasing, intimidation) that is intended to harm another.
In summer camp, exclusion is often the most painful kind of bullying. When campers experience exclusion, their summer is compromised because their social network is damaged.
Unlike other types of bullying, relational bullying is not as overt or noticeable as physical aggression. However, the effects can be long lasting.