Within a few seconds, another bird entered. Whether these birds are partners, potential partners or rivals, I have no idea at this stage.
This bird seems much more interested in the droppings on the floor of the nest.
It picks one up and flies out of the nest with it.
The only time I have seen this type of behaviour before is last year, when a female in box one found the droppings left by its partner male bird that was starting to roost in the box, undesirable and tried to remove them. She was soon overwhelmed by the volume of droppings the male produced and gave up.
You can see what happened then here.
I hope we don't have any of those sort of problems this year!
Finally, I thought I would show you a picture of one our favourite visitors the the fat block - the nuthatch.
I leave you with a reminder that our female blackcap is still with us.