My 6 year old boy is constantly in trouble at school. Usually the teacher says it's 'silly' behaviour, or not listening, not doing what he's told, making growling noises if something happens he doesn't like, stamping his feet etc.
At least once a week I am told that he has hurt somebody at school. Sometimes this is by hitting or pushing, but has also been by swinging them round by their coat until they fell over, by stabbing them with a pencil, or nipping/pinching them. 
I am also often told that he doesn't do much work. This week he actually threw his book that he was meant to be doing work in across the classroom.
Every morning I, and my husband if he is doing the school run with me, will say to him be good, do what you're told, be kind to the other children, get on with your work, etc. He promises he will, we have a kiss and cuddle and he goes in quite happily. Then at home time the teacher wants to speak to me about his behaviour.
I am getting to the end of my tether - I just don't know what to try. This week he had a tantrum at the end of the day because he'd left his hat in the classroom and the teacher wouldn't let him go back in to get it, so the other parents are seeing his behaviour and I'm sure he has already got the label of the 'naughty boy' in the class.
We have tried rewarding him for getting a good report from the teacher. A few weeks ago we promised a trip to a local attraction if he was good all week and he did more or less manage it (teacher knew we had promised that so was less harsh in her reports but there were still some things going on like him not getting his work done), but this week, on Monday, I promised a swimming trip on Friday if we got a good report all week and on Tuesday he got a terrible report about his behaviour. On Wednesday I bought him and his brother a sweet for after school if they were good that day and he wasn't. I reminded him this morning that the sweet was still in my pocket for after school if he was good, and today we got the worst report of the week!
We have also tried punishing him for bad behaviour. On Tuesday he sat in the car with my husband for half an hour while I took his brother to the park, but that made little difference to Wednesday's behaviour. We speak to him every night about his behaviour and he promises that the next day he will be good but very rarely is! Today I asked him why he had hurt people a school and he just couldn't give an answer - I think that sometimes, like when he stabs them with a pencil, he just does it for the hell of it!
So I would really appreciate some tips on turning this behaviour around! At home he's quite willful, but nothing like what he seems to be at school. He and his brother rarely hurt each other, yet at school he just can't seem to stop himself!
He does have a problem with listening and doing what he's told. Yesterday he and I were walking to go and collect his brother from a club and he picked up a stone. 'Put the stone down' I said. He pulled his arm back with the stone in so I said 'put the stone down, don't throw it' and he threw it - narrowly missing a car bumper. I made him hold my hand the rest of the way after that, but that kind of little thing just happens constantly, it's like a power struggle for him - he wants his own way all the time and won't listen!
Reading this back it makes him sound awful, but he can be a lovely little boy, and when we're out and about I often get complimented on his behaviour and manners! Basically, when he's doing what he wants he's absolutely fine, but anywhere where he can't be 'the boss' is when problems start!