I'm at a training today across the street at the community college so I went over to check on my 4th period who are typically good kids, but with a 1st grade level of behavior and self control. Sure enough, I walk in and they're supposed to be taking a test. They're all talking, admittedly about anything and everything except the test, on their phones etc. The sub isn't saying anything, class had just started so he might have but I doubt it. So I walk in, ream them out, and walk back out.
Who knows if it'll last for the rest of the period, but at least they were quiet for a couple minutes