Life Luna! UPDATED with a lullerfly link

I was doodling around in the garden last evening, pulling some of the taller weeds and looking at my plants, when I came practically nose to nose with this:

Click for lunatically large!

I don't recall ever having seen a luna moth before, much less two of them! I tried to look at them from the other side to see if (and how) they were, well, you know--doin' it, but it was too hard to get back there with the corn plants in the way. I don't think these two were mating; they didn't really seem to be touching any of the--er--important parts. Still--what are these moths doing?

Let's look more closely at this amazing moth:

Click for mothmonstrous!

First, I noted that what I thought were just plain old wing eyespots are in fact small holes in the wing, surrounded by differently colored accent cells. Amazing! I suppose such tiny holes in such large wings do not affect flight.

Second, look at those beautiful antennae; they remind me of palm fronds in their complexity. What do moths use their antennae for? I don't really know. Anyone?

What amazing creatures these moths are, as beautiful as butterflies yet classed in the moth family. Here's another question for you lepidoptary-inclined folks out there: what is the difference between moths and butterflies? Is it the eating-nectar thing?

UPDATE: For some incredibly beautiful southern butterflies, check out Troy and Martha's Ramblings Around Texas.

Moving on to my sunflowers: Last year, I had a whole row of mammoth sunflower plants. This year, I just left whatever volunteers that came up. Here's the tallest sunflower plant:

It was pretty late in the evening, so pardon the dark. The flower should bloom within a week or so, I believe.
Here's the plant with its neighbor:
That red arrow indicates my height. I'm 5'1".