During the last couple of weeks we have had some frantic activity by some bees, noteably in the Wood House, a play den for the boys and where they store all their toys and books on large shelving units. It was indeed these shelving units that were seemingly the focus of all the bees' attention and on closer inspection we could see why. The supports were drilled down their entire length with holes of about 5 or 6 mm and the bees were 'nesting' in these holes. We could see that some of them were completely plugged up and other were only half full. So the quest began to find out if we needed to move the shelving units for the summer for safety purposes.
Fortunately we found out that they were Mason Bees 'harmless to pets and children' (presumably to adults too) and that they are extremely good pollinators. So we decided to live and let live and watched fascinated as they came and went so many times filling the holes with granulesof soil after laying their eggs in them. At the back of the hole they lay a female egg that takes longer to hatch, and at the front a male one. Then they bung it up. Mesmerising.
Then we realised that the same activity was taking place in the drilld holes under our outdoor eating table and benches, but gain they troubled us not and just went about their business. It was good for the boy to experience this as they now know that bees, especially Mason Bees, are docile creatures that just want to get on with their job.
For more about them see http://gardening.wsu.edu/library/inse006/inse006.htm