Here is another example of a bluetit at play - this time just the female.
You can just see that she is bringing nesting material to the box.
Here she is inside, wondering what to do with it.
Twenty minutes later she brings another load - it looks a big one this time.
Yes - this is a much bigger amount than she has brought in previously.
She still doesn't seem to know what to do with it.
She finally decides to drop it on the floor.
"Is that right?"
No - this is clearly not good enough for her chicks, so she picks it up again ...
... and flies off with it!
"It'll have to go!"