There may be something going on with another child at the headstart that is bothering your child and he is not able to tell you. Many not so well of children are in this program. Some from horrible situations that we can only imagine. (Abuse and stuff) If that is not the situation then mabe he is trying for independence. Try giving him a little. Try to limmit the no's you tell them. Give options and consequences up front. I am trying to think of a good example and one is not comming. Maybe if they want a drink that is sugury you don't want him to have you could instead make it like it is his choice. Say you can have milk or juice or water. Which would you like. Give them options and stuff so they feel like they are in control and not you. Also for the temper tantrums. Unless they are in danger IGNORE, IGNORE, IGNORE. Temper tatrums are for getting there way. Don't ever give in. Don't even give eye contact. My daughters pediatrition told me this and it works. Also I learned much stuff from a parenting class. It was free through the local pregnacy center. Plus they help you out with things you may need for your children. Hope this helps.