Common Green Darner at the lights

Yesterday, when the Common Green darners did not appear to be migrating along the coast, and earlier this morning, when there was only one Anax junius in the shrubs bordering the meadow, I had a feeling, bittersweet, to be sure, that the odonate season was pretty much over. But this evening, I heard a rustle in the vicinity of the kitchen light and I spotted an ode flying around the bulb. Usually, there's only one species that appears after dark, but a quick look told me that this was not a Fawn Darner. It was instead a Common Green: the color and that weird "third eye," which is actually part of the insect's forehead, was diagnostic. But I'd never known this species to be crepuscular or, for that matter, nocturnal. Clearly, this A. junius wasn't reading my guidebooks. Perhaps it arrived because of the warmth of the light; it certainly stayed in the vicinity of the bulb. It was still close by the following morning, but in short order, it started to shiver to generate internal heat and as soon as its muscles were primed for flight, off it went... somewhere.