I'm a Cover Supervisor (so I'm expecting most people to discount my contribution straight away...). Anyway, when I started last September, I spent the first few weeks 'shadowing' other CS's and teachers. The first class I was given to have on my own was an all boys low ability group. Within 2 minutes of walking into the room, 1 boy had asked another why he was sat in 'his seat' - this instantly escalated into a huge fist fight, with blood everywhere, a boy in a headlock in the corner of the room, a fist cut open, a face cut open...! However, I survived, the boys were taken off to first aid / the HT, and I had to stay with the rest of the group for the remaining 60 minutes trying to keep them on task and to keep discussion of the fight to a minimum!