The same student I mentioned below in the history class found an annoying new trick a few days later.
Humming. Really loud. In the room were three adults... The regular history teacher, the college student, and myself. The teacher asked her to quit, so she started doing this:
Annoying student: MMMMMM... Oh shi... Sorry, sorry. Can't help it. MMMMMM.... Oh sh... Sorry, sorry, you see? I just can't help it. MMMMM... Oh there I go again!
I quietly walked over after about five straight minutes of this.
Teacherlady: Can I help you?
Student: No. I don't need no help.
Teacherlady: Well, it's just that you've been asked a number of times to stop humming, your friends aren't laughing anymore, so I figured you were doing it to get adult attention. Do you want attention, because you can just ask for it.
Student: I don't want your attention! I don't want to talk to any of you!
Teacherlady: Oh okay. Well, we just thought you wanted our attention. Next time, don't hesitate to raise your hand.
Again, she was silent for the rest of the class. I love my job. Sometimes, I even get to teach more than just manners.