During our very successful inspection of bat roosting and hibernation boxes in the late summer of 2017 we found one hibernation box which was obviously occupied by hornets. The presence of the large insects kept the inspection team a respectful distance away. The presence was noted and plans made to revisit the box in the winter when the cold weather would have killed the occupants.

When we returned many months later in the cold weather we found the insects gone and the box completely full with the nest they had built. It had to be emptied to give bats the opportunity to re-occupy the box. The nest had been constructed in a very skilful way to fill every centimetre of available space inside the box and included an area beneath as they had expanded their colony further. A few dead hornets remained.

The nest was carefully removed and the box cleaned out. Despite being an amazing example of hornet skill and ingenuity it had prevented the box being utilised for its intended purpose to house hibernating bats. We work hard to increase survival prospects for the diminishing number of bat species in our area so are hopeful that next year it is occupied as intended. We have found however that hornets often come back to the same locations on successive years so are slightly apprehensive that the problem might be repeated. We have asked for a volunteer to mount guard on the box next summer to drive any invading hornets away but so far there have been no takers.

 

                                                                            Unwelcome visitors have rendered this hibernation box out-of-action.       

                                                                                         An example of hornet construction skills found within.