Time For Underpants

In the middle of last week Aaron declared that it was Time For Underpants.  We had hoped for this moment to arrive around now, and Aaron has been doing a terrific job.  It takes a lot of practice, but he has a good model.

Today, while sitting patiently on the potty, Aaron looked at me thoughtfully and said,

"Pee is mostly water.  And poop is mostly .... poop."

I had been wondering how he would finish that sentence.  What is poop, mostly?  Wikipedia is unhelpful on this one, although I did learn that the "distinctive odor" is due to bacterial action.  While I was musing, I became aware that Dale and Jordan, back in the bedroom, were having a biological conversation:  Jordan had asked Dale how the vitamins from your food get into your cells.  Quite a question, really.  Dale, much better equipped to answer than I would have been, explained it with an analogy to gas exchange through a balloon full of helium.  Did you know that?

While I am posting embarrassing pictures of the children, I may as well include these: