Ds 15 yr and DD 12 yr seem to be constantly bickering, arguing. They bicker and fight about anything, everything and nothing, sometimes one of them just has to walk past, look at the other or make a slight noise. It is becoming intolerable for me and I dread the time they are off school. And yet I have been told by teachers, headteachers that they are really really good children!
I suggested to DH it is because they so often have only each other to rely on as at home our neighbours are elderly in the main and there are no other children for them to associate with. DH said that this should not be an excuse and if anything should make them more friendly to each other not less!
What do I do they are seriously driving me nuts with stress ( I have tried talking to them both calmly about it aswell as getting angry/upset) and told them they need to try harder, they are plenty old enough to see the effect their behaviour can have on others, mainly me! 
If anyone else is in or been in same boat how did you cope?