We’ve had a bird box on the back wall for years. Some years we’re lucky enough to get a couple of Wrens nesting in there, although last year some of the youngsters fell prey to a very bold Jay. The plan was to keep the nest box in place until after nesting season, then remove it.
We could hear a strange buzzing sound near the window overlooking the garden, and had noticed there were several bees flying around in that area. What we hadn’t expected, was for a group of bees to be making their home in the bird box!
We’re assuming that the moss & sticks that are sticking out of the box, were parts of the Wren’s nest material that the bees had pushed out of the box to block the entrance hole.
Looking at the before & after photos, ignoring the amount of mess on the front of the box(!) you can see the way the bird box has been pushed apart by the bees. I would never have expected them to be able to make something that would force a wooden bird box apart like that!
Having done some research, it turns out these are Tree Bumblebees (Bombus hypnorum), which commonly make their nests in empty bird boxes.
Find out more about Bumblebee nests at Bumblebee Conservation Trust