Different pair in the box both looking very uncertain.
Different bird now investigating the box - looking in from the outside through the hole. Looking very uncertain. More material brought in by the end of the day, the bare wood was nearly all covered.
Male came into box while female there and she hissed at him, he then left immediately. Heard chiff-chaff for the first time this year. Put wool in the wire container outside the nest. Female still bringing in moss and grass. Bottom of the box under the nest bowl is still bare wood. Female still pecking like crazy on the bare wood. Head butts the nesting material to compress it. Uses its chest to form a nest bowl shape at even the earliest stage when just a little material in the box.
Tapping of the hole and beginning to bring in nesting material.
Removed the straw I'd stupidly put in over the winter.
Previous year's ringed female inspecting the box.