Welcome Sally, this sounds a lot like my DS4 when he was a 3yo. I guess I would have to knwo more about your son though, like what his motivation is for this. What I mean by this is, is he trying to hurt them or is he just playing? Is he a big kid? Does he seem confused when others are hurt or are backing away from him? Does he seem to want friends?
There are so many different reasons for this type of behavior. When my DS3 was in school the teacher mentioned he was knocking kids down and that he was "aggressive" when I asked more and observed, she then stated that he never actually means to knock kids down he just plays too rough. See there is a big difference between a child that doesn't know their own strength and isn't sure how to play and a child that is aggressive and trying to hurt peers. Another example of this is when my child was around a group of peers and they were playing a board game. he wanted to play and they had already started a game. He took their board and threw it on the floor. When I heard this I was shocked...but when I talked with him later he simply explained that they would then have to start over and he could play. I give that example because things are not always as they seem. I would look into this more with him. Maybe go and observe and see what is going on. My son would wrestle and play with peers, he was used to playing tag with friends and didn't realize how hard he was tagging. At 3 it was too bad but we had to have a rule at school about not touching his friends because the school had such a problem with it. Now at 4 this isn't an issue. Anyhow, please let us know more if you know more. : )
