At Leighton Moss bird hide, I noticed the usual dozens of dead flies on the inside window ledge. But there was just one fly still alive and very active. It ran around the ledge searching for its dead companions and then deliberately jumped on each one and 'hugged' them. It particularly was obsessed with green coloured flies as it jumped on these with particular relish and proceeded to wrestle with them. All its legs were wrapped round the dead fly and it rolled over with it clasped in its legs, before moving on to the next corpse. The few wasp corpses were tiptoed round; it certainly didn't jump on these!
What was going on?