Barney's back for another look. And this time he enters the box.
This time Fluffy comes to the box when Barney is inside. His reaction is to cower down.
Fluffy decides to go into the box and for a brief moment they are both inside with Barney the submissive one on the right.
For a couple of seconds Barney stays frozen - then he's off, leaving Fluffy by herself in the box.
Sometimes she leaves quite soon after Barney, sometimes she stays for longer and appears to be inspecting the nest box or sitting on the nest box hole looking outside.
However, it is worth noting that Barney never tries to enter while Fluffy is in the box.
We cannot remember whether the male starts to do that once the female is sitting or only after the chicks have hatched. We shall be looking out for that this year.
This sequence is repeated several times each day and because it appears to be common to all bluetit pairs we have observed over several years, it must have some positive outcome. Whatever that is, at this stage to us it is a mystery!