I'm not sure what I'm doing wrong.

I love B to death. He is the cutest, most lovable little dude ever. He's also a total jerk.

I've been noticing that he is the bully at preschool (one day ones program--I'm there), My Gym, and when I nanny/have play dates. B snatches toys from other kids, immediately wants what everyone else has, plows down other kids to get what/where he wants, etc. he's really big for his age and uses his size to physically push and knock kids out of his way. It's so embarrassing!

At first I thought it was normal behavior for his age (17 months) but none of the other kids in his classes are like this. I reinforce taking turns, make him give toys back when he snatches, and use lots of positive reinforcement. I don't know what else I can do.

Please help me prevent my kid from being the class bully!