'Mike' wrote:
Once they leave, 'they', but I don't know how many there are, will
they all leave at once and am I correct in saying that once they have
gone .......... they have gone?

I don't think the chicks ever go back in once left. But some might stay
overnight after the bravest have left. And the parents might take a while
before they are convinced the box is empty and so keep visiting.

Mike (whose nest box only has dead chicks in now).
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