Night of the Moths

I don't know what species of moth it was, but last night I was surprised to see moths by the thousands flying as I drove the area's wooded roads. They fluttered up and over the car, even though it was early December and the temperature was in the low 40's. It makes one wonder, how? why? Is there an advantage for the adult stage to be out at this time of year? Less competition? Fewer predators? It also reminds us of how adaptable is nature.