What is a bully?

When one of the horses in the pasture keeps making fun of my spotted rump and I have asked them not to do it-that is bullying.
When Quincy, my pasture mate, keeps stealing my treats before I can get any-that is bullying.
When the fancy show horse in the pasture won't let any of the horses talk to me-that is bullying.
Teasing Delani because he is shorter than the rest of us-that is bullying.
Making fun of how Salty walk with his bum knee-that is bullying.
If I started biting all the horses who are doing the things above that would make me a bully too! 
"Courage is fire, bullying is smoke"