When I stopped to look closer, it looked a little beat up, so it must have been there for a while. It appears, though, this is just the beginning of their season, which runs through August. That makes me think there must be more out there, somewhere.
In the day time, it just looked big, but I’m not sure I’d want to see one flapping about at night. So, if you happen to be out after dark, especially with a flashlight or a porch light—beware!
Something might just come looking for you…
After my initial surprise at finding the moth, I picked it up (with a couple of sticks) and brought it home to take some photos.
Then, a little research found that this is an Antherea Polyphemus, or Polyphemus Moth, named after the Cyclops in Greek myth. The OSU Insect ID Clinic also notes that Polyphemus Moths generally emerge from mid-July through August, with a 4-6 inch wing span. (The website has photos of some other strange looking critters, if you happen to like bugs.) My version looks pale, compared with other photos I found—and a little dilapidated. Still, it's pretty impressive.
Now I'm feeling like The Girl of the Limberlost.