At first I wondered whether someone's dog had been around and dug, but on closer inspection I could see bees moving about in the hole. When Chris saw the remembered seeing another similar hole further up the road. It looks like a badger had come along in the night and dug out a bees nest from the ground. When I went down just before leaving for work I could see the bodies of many bees around the hole, and lots of bee activity inside, presumably repairing the damage.
There has been a bit of a furore over here about both badger culling and how many bees are dying. I'd say that the badger population has grown considerably in the last 20 years in this area, to the point where a sighting isn't special, and they may be one of the reasons bee numbers are decreasing.