Gather the kids in a group. Allow the children to feel bonded in the experience. If there are cliques in the group, separate them so everyone is sitting next to someone they wouldn't normally talk to.
Ask the children to name ways that rumors get started. Write their answers on a chalkboard or dry erase board so everyone can see the answers. Responses might include "trying to fit in," "eavesdropping," "getting revenge," or "feeling jealous."
Explain that rumors always come from a place of insecurity. Ask the children to reflect on the last time they felt totally loved, secure and happy. Ask them if they'd ever start a rumor from that state of mind. Help them understand that rumors are started by people who feel bad (either consciously or subconsciously) and want others to feel as bad as they do.
Ask the children who have ever started a rumor to raise their hands. Ask children who have ever been the victim of a rumor to raise their hands. Encourage them to discuss their experiences. If there are no raised hands, discuss your own experiences.
Start a rumor. Whisper something in a child's ear and have her whisper it to the next person. Allow the rumor to travel through the room until it gets back to the person who started it. Speak the rumor out loud. Point out how different the rumor is from when it began. Explain that not only are rumors hurtful, they are rarely (if ever) true.
Inform the kids how to stop rumors in their tracks. Explain that they can't always stop a rumor from starting, but they can always stop it from spreading. Remind them they don't have to repeat any negative comments. Arm them with retorts for the rumor starter, such as "I don't like to talk about people behind their back. Let's go include her in the conversation" or "I don't want to talk about that. I wasn't there to see it" or "Do you talk about me like that when I'm not around?"