The Eurasian wren (Troglodytes troglodytes) is a small bird. It is polygynous; male birds have more than one female mate. Male wrens build many nests for their females to choose from.
The scientific name is taken from the Greek word “troglodytes” meaning “cave-dweller”. The wren likes to hunt and roost in cavities and crevices.
When we see a wren it is usually perched on top of a brash pile, presumably the perfect place for Mr Wren to build nests for the delectation of the Mrs Wren(s). They are difficult to get a photo of as they never sit still for long.