The great tit enters Box1
The bluetit hasn't given up on Box1 yet!
Ten seconds later the bluetit appears.
First he moves to take a closer look
Then he flies across to the other side of the roof.
The great tit is clearly not much threatened by this bluetit's behaviour.
Another look into the nest box.
Suddenly, he looks up. What has he seen?
We'll never know but whatever it was, he left right away.
Half an hour later he's back for another look at the box. This time it's empty and we are hoping that it will go inside.
He perches on the entrance hole and appears to consider what to do.
In the end he decides not to risk going inside the box and flies away.