On my normal Lockdown Walk I have observed a pair of Long-tailed Tits building a nest. They have to my knowledge been spending the last five days building and the nest is not complete yet.
If you have never seen a LTT's nest it is a complete work of art.
It is bottle shaped with a dome roof with a small entrance hole.
It consists of moss and feathers interwoven into upright branches of a bush.
The whole structure is camouflaged with a cover of lichen.
It can take three weeks to complete.
The image below shows moss in the birds beak.
Below the bird has just plucked moss from a lateral branch.
Below you can just see the lichen in the birds beak.