A frenzy of insects, including moths, butterflies, ants and flies, were very attracted to something in two splits in the bark of a small tree. They were undeterred by the camera and were still there when I returned more than an hour later. When I went back the next day there were no insects, but there was a smell of vinegar so it seems likely that the attraction was fermenting tree sap. The insects certainly look quite drunk in the video I took.