I'm a PGCE science student with a class of year 7s whose behaviour is known in the school for being challenging. I've observed them with other teachers and they are worse with me than with the others. It's an area of focus in the final weeks before my final report, and I'm concerned that in the limited time left I won't have shown I can get them on side! Particularly, I have trouble spotting who is responsible for something. If I turn away from some students (which in a lab like ours is impossible not to do without strafing around the edges of it like a paranoid schizophrenic), they will often start a game of 'who can get away with shouting something random/rude / making animal noises. This noise, once started, then bounces around the class between three, four, or maybe more students. I'm having a real time trying to pin down who did it, and they know I can't figure it out which makes it all the more humiliating. Above all, it's becoming increasingly frustrating and I'm finding it harder and harder to stay the 'cool bureaucrat' - what should I do?