The wren is Denmark's second smallest bird, only "surpassed" by the goldcrest.
It is easily recognizable both in terms of appearance and sound. It is a small, compact bird with a tail that always stands upright. It is also not particularly shy, which means that you have plenty of opportunities to see it.
It also has a very powerful and easily recognizable song, and unlike most other birds, you can hear its song all year round.