This little wren has been visiting our garden for a while, but I have never been able to photograph it – until now. Even so it only stayed still long enough to eat the bug. The light was a bit low, needing an ISO of 32000, resulting in a fair bit of noise.
Wrens are medium-small to very small birds. They range in size from the white-bellied wrens, which averages under 10 cm (3.9 in) and 9 g (0.32 oz), to the giant wren, which averages about 22 cm (8.7 in) and weighs almost 50 g (1.8 oz). The dominating colours of their plumage are generally drab, composed of gray, brown, black, and white, and most species show some barring, especially to tail and/or wings. All have fairly long, straight to marginally decurved bills Wikipedia.
The RSPB website also has plenty of information about these birds and how to participate in the Big Garden Birdwatch.