What causes a bully to be a bully?

Our grand kids lived with my husband and I for 8 years.  We didn't intend to keep them that long but it just worked out that way.  I knew early on that 2 of them, Aurorra and Tristan, were different.  Aurorra was always a little quirky and Tristan was always like a bull in a china shop.  He would just do whatever he wanted and didn't think of the consequences.  He was kicked out of a mother's day out program when he was 2 because the teacher just couldn't handle this energetic little boy that never seemed to sit still and was always into something. We decided to home school them when Arkansas implemented common core. I had read a lot about it and knew I didn't want the kids in a school that taught common core studies.  Another reason we decided to home school was Tristan. He was in kindergarten by then and always in trouble. He was bored and just couldn't seem to sit still for long.  We took him to the doctor and got the usual prescription for ADHD medication.  It did help him in school only because it zoned him out and he didn't have any desire to cause trouble.  I hated it because he just wasn't our Tristan when he was on it.  Now Tristan is all boy but the medicine made him more like a zombie......I hated it.  We home schooled for 3 years and then they went back to live with their mother and that meant they would be back in public school.  I knew Tristan would have a hard time adapting because he has always been a creature of habit and doesn't like change but I thought Destiny and Aurorra would be okay.  They both did fine when we lived in Arkansas and I thought that would continue in Louisiana. I was not surprised that Destiny thrived in school.  She has always been very competitive and loves to be the head of her class and all the praise that goes along with that.  I was surprised at how bad Tristan and Aurorra have been bullied.  Now I know Aurorra is quirky but she is quite the social butterfly so I thought she would fine her niche....she didn't.  Middle school is terrible especially if you are a little different.  The kids have been ruthless to the both of them and what is even more sad is the lack of empathy from the teachers and faculty at the school.  So why are they bullied?   What makes a child or young adult think this is acceptable behavior?  Does it start in the home? I always told the kids if I EVER found out they bullied or picked on anyone life for them would become very difficult. I guess parents don't do the same with their kids.  I think it is so sad that these 2 kids, and I am sure dozens more, hate going to school everyday because they know when they get there they will be picked on, insulted, and tormented the entire day.  I think it is sad that you have kids in middle school committing suicide because they just can't take the bullying anymore and what is even sadder is the parents of the bullies don't seem to teach their children that it is wrong to pick on or bully someone just because they are a little different or don't fit in how you think they should.  God made us all different, that is what makes us great.  How boring would life be if we were all the same?  Being unique or quirky shouldn't be seen as a reason to pick on ANYONE. I know Tristan and Aurorra just want to be accepted for who they are.  They are amazing kids who just want to be liked, they want to have friends and do the things kids their ages do.  Bullies make that almost impossible. Most days I just want them to come back home so I can teach them here and protect them from the jerks and bullies of the world but I don't know if that is the answer. Will cause more harm than good? Maybe for just a couple more years until they are old enough to understand the hatefulness that is in the world and be able to stand up for themselves. Their mom is doing an amazing job and everything possible to protect them but she can't be at the school all the time.  She can't be there to stop them from being bullied and she can't count on the school to step in and stop the bullying from happening.  So what is the solution?  I wish I knew but I am afraid of what could happen if they get pushed too far. Please pray for the Tristans and Aurorras of the world. Pray that they are able to ignore the ugliness that is around them and concentrate on their studies. Pray for the bullies of the world that they would open their eyes to the damage they are causing with their behavior.  Pray for the parents of the bullies that they would see the damage their children are doing to other children.  Pray for the parents of the bullied that they can make their children understand that there is ugliness in the world but they are special and loved.  

http://www.bullyingstatistics.org/content/facts-on-bullying.html