I'm quite an experienced teacher and feel embarrassed about having behaviour problems in my classes. Last year I shared a class with a colleague, and while they were her favourite class, they were my worst. She constantly praised them to me and told me how great they were, while I dreaded them every week. This year, I share another class with this same colleague, and after my first lesson with them, I pointed out to her on the seating plan which ones to look out for as they might prove a problem. After her first lesson with them, she said she loved them, they were good as gold, and not a peep out of any of the ones I had said to look out for. This really knocks my confidence and shuts down any meaningful communication I can have with this teacher - she seems to not find them a problem at all, whereas I can't get them to behave properly. Last lesson, two pupils decided to just get up and walk quickly around the whole classroom a few times. Others were throwing felt tip pens. I wanted to put them on detention, but was worried that if I did the other teacher would see and act all surprised and shocked that I couldn't get them to behave. So I kept the students behind, told them how inappropriate their behaviour was and how I don't expect them to behave like that again. I said if they did, it would be immediate detention. Now I feel like a failure for not putting them on detention straight away, which I think is what I should have done. On an aside, I think my problem is mid sets. These two classes last year and this year that I have struggled with have both been large mid sets - I'm good with top sets and bottom sets - I know how to differentiate for them and deal with their learning behaviours. The problem with the mid sets is the low level off task behaviour, like calling out rather than putting your hand up because they are keen and want to contribute, like talking with their partner about the work when I've asked for it in silence, and I'm not sure if the other teacher just lets them get away with this as she doesn't mind, or if they don't do it with her, or if she keeps stopping the lesson to address these behaviours. At the moment, I keep stopping to insist on hands up and silence for individual work, but it feels like I am just doing it all the time and creating a negative atmosphere in the classroom. I also keep changing the seating plan every lesson to find the right place for some of the chatty ringleaders, but wherever I put them it seems they are close to someone they shouldn't be close to! Can anyone give me any help or advice on this? Thanks!