What can I do about undergraduate students cheating? So I lecture at a university on the department of mathematics and statistics, and this year I am teaching calculus for future mathematicians. One good thing about the mathematics course is that very seldom I have seen students cheating, since people who choose the academic path are more bound to be interested in learning the subject rather than just trying to obtain a diploma.

Well... At least until now.

There is this small group of students who sometimes whisper during the tests. The other times their class had tests I thought they were asking for an eraser or something like that. But this time they were whispering more than usual and they started stopping after I glared at them. I thought it was suspicious so I waited until the end of the test and went to check their sheets and ditto. They all wrote the exact same thing. (For those familiar with maths they didn't copy a thing or two, but two actual entire theorem proofs.)

Now next time we have tests I could try separating those guys, asking them to sit on other chairs, staying behind the class in order to make it difficult for the students to cheat and stuff like that, but in all seriousness... Those measures make it look like I'm dealing with kids. I'm not a teacher. I'm a professor. I shouldn't be dealing with kids.

Basically I want to do something about this but I don't want to start making the class look like a high school. Those guys are future math teachers/professors and I'll be damned if I have to organize the class preventing future professors from cheating like this was a normal occurrence.

So what should a professor do in this situation? Are there any things you fellow professors have done and worked? Thanks in advance.
Unless you have very weird exam regulations or are allowing people to take exams in groups, no one should be talking to anyone else except via the proctors. I would view this as an infraction of the exam regulations and stop them from proceeding with the exam, and file for the appropriate sanctions.