Their scientific name 'Troglodytes' means cave-dweller, after their preference for cave-like places. These little birds are nicknamed Jenny Wrens.

Physical description
At a length of 9.5-10cm, wrens are the second smallest birds in the UK, after the firecrest/goldcrest. They are russet-brown with a paler underside. The wings, tail and flank are barred, as is the back, but less distinctly. They are rotund with a short, upturned tail. Wrens have a pale eyestripe. The different sexes and ages look similar.

Distribution
Wrens inhabit Europe from the Arctic circle down to Sicily, the Mediterranean islands and southern Russia; and also in Asia, north west Africa and North America. They are widespread across Britain including the Hebrides, the Shetlands and St.Kilda.

Habitat
They live in a variety of habitats that provide low cover, including woods, hedgerows, gardens, marsh edges, reed beds, cliffs and rocky islands.

Diet
Wrens are ground feeders, rummaging through the undergrowth for insects and spiders.

Behaviour
Wrens are mainly sedentary in the UK, although some migrate from the continent (usually Scandinavia) from October to April. Wrens are diurnal, but will sometimes remain active after sunset. They are not social during the day, but may roost together at night, especially during the winter. As many as ten have been found packed into a coconut shell, and 46 were counted in a single nest box. They fly rapidly and close to the ground.

Reproduction
The cock builds a large domed nest, often in ivy, buildings or between rocks, and the female lines it with feathers. The female lays about 5-6 eggs which she incubates for about two weeks. When they hatch, it is the female that takes responsibility for feeding the chicks. The young can fly after about 16-17 days. Two broods a year are normal. In areas where food is scarce, wrens are monogamous, but in richer sites the males will breed with more than one female.

Conservation status
Wrens are the most abundant birds in the UK, and there are currently around 10 million pairs. They suffer from heavy losses during the winter - 75 per cent of British wrens were thought to have died during the harsh winter of 1962-3.

Voice
The wren has an incredibly loud voice for such a small bird. The song is a long, excited verse, with many trills and metallic ringing tones. The call is a sharp tic-tic-tic, which accelerates into a rattle when the bird is alarmed. Wrens sing mostly from cover, and sound like no other British bird.

Notes
Until recently, wrens suffered at the hands of a cruel ritual in Britain. On St. Stephen's day (December 26th), youths would beat wrens out of the hedgerows and kill them. Fortunately, this practice no longer continues.

In America, this species is known as the winter wren.