I'm not an expert on the subject of bullying, but I'm going to give you my unabridged opinion straight from the gut. Google is full of do's and don't regarding this subject. However, I will follow my natural inclination and look within.
My mother taught me a valuable lesson: to always respect the dignity of others, and accept nothing less from another. I learned the importance of standing up for myself regardless of circumstance and that there are times when one must never back down.
She did this by empowering me to believe in the sanctity of others and of myself. She showed me reflections of myself as important and valuable, but insisted that my power meld with others. There is nothing more empowering that to feel rooted in your home and significant in your community!
It is my natural inclination to break the face of a bully but my thoughts today ask you to look at yourself. Pay close attention to what you're teaching your children. Children learn to be bullies!
Do you value rational thought but feel uncomfortable with emotions? Are you aware that children often tease others for their emotional expression, and that common put-downs seem of little consequence but hurt deeply? They are words that promote an order of dominance enforcing behavioral norms and should not be tolerated.
Do you value only excellence and success? Are you aware that when children have no room to fail they become impatient and critical of others?
Do you foster a culture that values the diverse nature of individuals? Do you allow and encourage a diversity of opinion and thought?