Voyager EMH
Slipper Wearing Plucker of Pheasants
There's a theory about blue tits and collective learned behaviour.This could also be posted in random irritations, but.
Why is a Blue tit sitting on my shiny brass front door handle and tapping away with its beak ?
it has been doing it the last couple of days.
If your front door has a keyhole, letterbox or other features, it may resemble a bird box as a potential nesting site.
Blue it could be figuring this out.
Or it could be just having some fun.