School Problems ~ When The Classroom Comes Home

“I have a 5 year old son that is in kindergarten.  He loves school because of all his friends there…  Unfortunately with school I see him still coming home with some bad habits that we must work to break.  I think his teacher is great but with all the kids in the class she can’t be expected to enforce/reward self-government principles.  My concern is that he is getting confused with discipline at home and less discipline at school.  How do you address this issue with your kids?”
It is hard to have a child come home from school with behaviors you need to break all the time.