On Close Inspection....

...this Great Tit was inspecting a bird box on my fence, and went in it a few times, but seems to have left it alone since, I'll keep an eye out....

The good news is the bird box has got a small fixed good camera in it, which, when I can get a connection on the mobile, shows crystal clear colour images. If the bird does nest there I'll look forward to cursing the temperamental app that gets the video/images.... :-)