Eurasian treecreeper (Certhia familiaris).
It has a long curved beak. The look on the back looks like a tree bark. The belly has white feathers.
There is a very good disguise and it’s hard to notice.
It is about 12 cm long and weighs 7 – 12 g.
Typically, the nest sits low – from 1 to 2.5 m in hollows on the trees where the female lays and incubates 5 to 6 eggs.
Parents feed their babies up to 260 times a day.