You would think or perhaps hope that with age and maturity they would grow up and give up their bullying ways, but that is just not the case. Since he is just short of five we had a very simplistic discussion about what to do about a bully.
It is rather late and I don't have time to recount our discussion in its entirety here so instead I will try and sum it up and give some insight as to what I may say in the future.
The bully uses fear as a tool. It is a weapon that he/she employs to try and coerce you into doing what they want. Often the best way to deal with a bully is to stand up to them and let them know that you will not tolerate their behavior and that no matter what they try you will not back down.
In the schoolyards of my youth bullies were dealt with and dispatched with fists. You didn't want to fight, but if you were forced into it you did what you had to do and you made sure that the bully understood that they had no power over you.
Unfortunately there are some misguided fools who fail to recognize their own failings and foibles. They will continue to fight and growl long after it has been proven that they have no teeth.
So the question becomes one of whether you give them any recognition. Sometimes you can just ignore their meaningless drivel because it is clear they operate from a place of fear and insecurity. They are so frightened and uncomfortable in their own skin that there is nothing that you can do to them that is worse than leaving them to sulk by themselves in a corner.
As I mentioned earlier this is a little sophisticated for a young child so I tried to do what I could to boil it down, but I was only partially successful. So I gave in and read part of one of my favorite Churchill speeches because it says so much. It sends a very meaningful message. Here is a link to the speech and my favorite excerpt.
"we shall not flag or fail. We shall go on to the end, we shall fight in France, we shall fight on the seas and oceans, we shall fight with growing confidence and growing strength in the air, we shall defend our Island, whatever the cost may be, we shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender,"
Speech before Commons
(June 4, 1940)