My 3.5 year old son has been pinching every now on then. We have another 2 year old daughter. Recently, the problem has been getting worse, he has started pinching/scratching his teacher in the pre-school. He also gets angry when he doesn't get what he wants and starts pushing his classmates and sister. He also started pinching his parents. We have been communicating with him and he also communicates back. So, issue really with impulse control.

Does any one have suggestions to calm him down and channel his anger?