Reclassifying People as Vehicles

I don't know how it started, why he's doing it, or what the rhyme or reason is to his method (if any) but for the last month or so, Dexter has been reclassifying people as vehicles. Most often, Dexter is a dump truck, My Bologna is a trailer, Daddy is a pick-up truck, and I am a cement mixer. Lately, he's been pointing out people in the park or grocery store and classifying them as well. "Look at that fire truck, Mommy."