Bullies will go away if you ignore them. Some bullies may go away. But others will get angry and keep bullying until they get a reaction. All bullies have low self-esteem. That's why they pick on other people.
Some bullies have high self-esteem.
They feel good about themselves, and picking on other people makes them feel even better. Most of the time, bullying isn't about high or low self-esteem. It's about having power over other people. It's tattling to tell an adult when you're being bullied. It's smart to tell an adult who can help you do something about bullying.