why do boys like dirt?

I've been doing some yard work with the wheelbarrow the last few days. (and thus ignoring my house) So I was doing the dishes, and the boys were outside playing. I went to check on them and this is what I found. Cute little bug! Just playing in the dirt naked. Does life get any better for a 2 year old little boy? So I went and got my camera, and Zack followed me out. He said, "don't worry mom, I'll tickle him, and then he will smile at your camera." He's so funny.