Cheating in school

Your child tells you that somebody in class is copying answers from his test papers, and he doesn’t like it. Should he tell the teacher?
The answer is, probably not.
Cheating is wrong, and he should not be a part of it. But shielding his paper should do the trick and may even send a message to the teacher without him saying a word. If that doesn’t work, he should get the miscreant alone and say something like “Look, quit trying to crib from my test papers. You know what you’re doing is wrong. Others have noticed it, too.”
In the unlikely event that these tactics fail, the teacher should be notified.