Lightning bugs at sundown

In the last week I'd noticed lightning bugs had gotten active as the sun went down, then stopped once real darkness arrived--there is a definite sweet spot (at least here) that doesn't last very long. They seem to prefer heat, high humidity and no wind, all of which we had last night. So I set up my camera and took twenty frames, each 30 seconds long at ISO 100. Entered them into Sequator using the "trails" setting to reveal what ten minutes of activity looks like.

Canon SL2 DSLR, Tamron 19-35mm lens used at 19mm, tripod, remote shutter release

Sequator, then cropped and added contrast