Bullying is unwanted, aggressive behavior among school aged children that involves a real or perceived power imbalance. The behavior is repeated, or has the potential to be repeated, over time. Bullying includes actions such as making threats, spreading rumors, attacking someone physically or verbally, and excluding someone from a group on purpose.
A common reason that a kid is a bully is because he/she lacks attention from a parent at home and lashes out at others for attention. ... Very often parents are bullies, are angry, or don't handle conflict well. Kids usually bully because they learn this behavior at home. It is learned behavior which can be unlearned.
Some kids are just more aggressive, dominating and impulsive by nature. It doesn't always mean that they are bullies.
Bullies dominate, blame and use others. They lack empathy and foresight and have contempt for the weak. They see weaker kids as their target., and don't accept the consequences of their actions. They crave power and attention.