River of bats

We sit outside most evenings after supper. If it's still, we usually park ourselves in the screen tent to avoid mosquitos. Last evening there was moving air, so we sat elsewhere in the yard. We looked up, probably sometime between 8:15 and 8:30 and saw hundreds, or perhaps even into the thousands, of bats against the sky in a bendy stream, almost a Milky Way of bats. The larger ribbon seemed to be headed toward IH-35 but another ribbon bent off to the west. They must have been among those leaving the Congress bridge not long before. The sun had set but the skies were not dark.