I wish I could thank everybody for their responses.
Why should he not volunteer for anything during basic? (I’ll relay that advice to him.)
Once you volunteer for something in basic, the drill SGTs will be asking him to do detail (chores) after detail after detail. They are lazy too. One thing I was told before basic was to keep your mouth shut and never volunteer for anything.
We had a guy in my BCT who always volunteered for KP and didn't graduate because he missed too many classes. Your son needs to be in class and on the ranges, not doing every detail there is.