One more thing about “calling security,” is that even if the kid is sent home or to the principal/dean’s office that day, she will be back the next day or the one after that emboldened and just as bad as ever. As far as that student is concerned, the worst that can happen is she gets a couple of days off of school. Many of these students just LOVE a day off of school. As far as they’re concerned, they’ve “won,” and they will have no motivation to improve their behavior.

And let’s just assume you keep calling security every day to get these kids out of your classroom. Do you want to know what the administrators will say? They’ll tell you that you are clearly not capable of doing your job if you have to keep calling security and suspending your students all the time.