I found Tyler eating a dog biscuit. His brother fed it to him.
Tucker was handing out dog treats by the handful; Molly was thrilled, and Tyler was exploring the new taste sensation.
I interceded quickly, in a major way.
(I should have been alarmed by the piles of giggles downstairs... but silly me. I thought they were simply enjoying each other. I should learn that 'enjoying each other' at this age is almost never fault-free.)