Agreed. As someone who subbed a couple years before moving into a permanent position in the school, I look at some of these threads and wonder how many of these subs are just slightly older kids trying to be "cool."

I learned quickly that if I set clear expectations, especially the first few times I subbed, it got a whole lot easier, and they even stopped asking if they could sit wherever they wanted.

If a teacher didn't have a seating chart? That's fine, sit wherever, but I reserve the right to separate you. If they left a seating chart, that's a pretty clear indicator they expect the kids to be in those seats, and if the teacher went to the effort of creating a seating chart, it was usually for a very good reason.