Matt's boxes 2023

Last year the BT pair that nested in my tree box did a similar thing - there was a lot to clean up after a winter roosting GT and they went on a real mission.
Fascinating behaviour, and not something I was aware happened until I saw it on camera!
I'm sure like Paul says this indicates they've pretty much chosen the box - unless any other takers muscle in or something bad happens like predation or whatever, it's looking very very promising I'd say.