Why?

Why to toddlers feel the need to draw on themselves with any available writing utensil? It's not like we have no paper or coloring books. Do they have some aversion to clean skin? You would think I might have some insight here after 5 kids. It's not like he is the first to do this, nor is this his first try at self body art.

At least he doesn't hunt down pencils and eat the erasers like his co-conspirator loves to do.