A bird was observed in the house almost every night. Somebody who knows more about birds told me that these winter birds are other individuals than the summer birds.
There are now 4 eggs in the nest. Each day a single one is added. In total there will be 6 eggs.
We can see very small birds, probably they came out June 1 or 2.
The chicks are huge now, they completely fill the nesting box. We can clearly observe two parents feeding the chicks. The one in the nest does not leave before the second one is in the garden.
All the chicks died because we have had some very hot days. Probably the dark colour of the box and the thin walls made the temperature extremely high inside the nest.