Chewy

I'm teaching about nouns- a person, place or thing.  The kids are all at their seats and I'm by the doc cam doing a worksheet with them.  I look over and little J is CHEWING on the shoulder part of the t-shirt of the kid next to him.  This alone made me stop and stare.  Then I couldn't help but wonder, "Why is kid B (t-shirt wearer) not doing anything about this?", like it is totally normal for the kid next to you to suck on your shirt during grammar.