My workstation is strategically placed where I have a good view of the garden. A herb bed is nearest which attracts insects of all kinds but rarely one as big as this. J jumped to the conclusion that it was a hornet.
My next observation in this area, entomologically speaking, was of some similar insects around what was clearly a nest hole in the rotting stump of a dead tree.
They have constructed a complex entrance to the nest out of a paper like material they make from chewed up wood and in some of the images one insect is standing on the left of the opening beating its wings, presumably for ventilation.
Which one is the hornet? I posted the upper pictures on Twitter and several #tags (as well as a fellow wildlife watcher) that the insect I had seen feeding on our mint flowers was in fact a HornetMimicHoverfly, which is quite rare and harmless. The second set of images are in fact Hornets– but not, thankfully, in the garden. The two insects are similar but those in the know advise me that the hornet has longer antennae and two sets of wings as opposed to the HM Hoverfly which has only one pair. They do sting but apparently they are not as aggressive as wasps.