This underwing moth flew into our house the other night when I opened the back door! It was attracted to the back porch light and must have been sitting on the door frame. Underwings are pretty fantastic and have been a favorite of collectors and evolutionary biologists for a long time. The upper wings are shades of gray and brown and are perfect for camoflouging the moth during the day on tree bark. The underwings, where they get their common name, are typically brightly colored and are shown when the insect feels threatened. It is thought that this bright flash of color either startles the attacker, or is enough to disrupt the search image they have and allow the moth a few precious seconds to escape. They are very strong fliers and this one flew all around the house in an erratic way and then would settle down very briefly until I came within about a foot, then it would take right backoff again. I finally cornered it in a bathroom, shut the door and was able to get these photos. I'll look it up in a great book on underwings (which I think is now out of print) Legions of the NIght (buy it if you can find it!) and post which species it is. Enjoy.