Jackdaws in the Belfry

Derek writes:

Jackdaws are hard working and persevering. They have been at St. Margaret’s  for years if not centuries.
They are keen to get in to the Belfry to make their nests, thus any opening has to be securely covered with mesh to let air in and sound out.
Over the decades the Jackdaws had broken through the outer mesh and filled the window cavity with thousands of twigs.
It was only a matter of time before this wedge would have collapsed the inner mesh and the plug fallen on to the Belfry floor, as per last year.
So Shaun, Bailey and I spent a satisfying, if not dusty few hours removing the inner mesh, twigs and dirt and then fixing new defences.
A job well done but we need to be on our guard as the Jackdaws usually have the last laugh.