My first period class has three "mean girls." I've had defiance from all of them and they are rude/don't do any work. One of the girls consistently was turning around/talking to the student behind her so I asked her to move her seat. She refused to move seats (already happened twice) and got a detention for defiance. Anyways, I wrote up a few names on the board for missing assignments and a math challenge problem on the back board. I had a few students in my homeroom who erased the board when I was watching the hallway and one student who erased part of the board while I was checking homework. I am 100% sure it was this girl and another student told me it was her, but I didn't see it. This girl got up to get a tissue about 10 times so maybe I can just say that she can't get a tissue and that she can bring her own? Obviously, I cannot be watching the board at all times. What would you recommend that I do in this case? I already wrote up this student two days in a row and my VP said that we have to call mom in to talk to her. I know these students cause issues in their other classes as well.