I would say he's either figured out that this sort of behavior will get him the heck out of the classroom and school as a relief, or he's very, very stressed about something - chaos in the classroom, bullying...I guess lack of challenge could come out that way if he's at his wit's end.
If you haven't seen this before it's something new that's happening with him or a build-up I would think. If you're seeing it at home for the first time it's probably a spill-over from school but your DS is trying to tell you something. You'll have to work on, over time, getting him to articulate
I probably sound like a broken record but also consider diet/allergies which can affect behavior and a friend of mine's son has that PANADAS which not everyone believes but it's strep throat time and that's his very worst time. Is there strep throat in the classroom in our state the school has to send a note home per the health department but you probably would have had this issue in prior years, also the food (others might be able to talk about onset).
I'd go with rather extreme stress?
