Why are teenagers so hateful?

I'm living with three of the monsters and I'm trying to give up smoking, unsuccessfully. They would drive anyone to drink!! I cannot remember ever being so annoying as my kids. They are driving me demented. Help! What can I do to stop the fighting, swearing, bickering, shouting, screaming. I have an older son who at the time I thought was bad but now I realise was an angel comparing to these 3 miscreants. But I love them really. Their ages range from 13 to 15