Nuthatches
One UK species, with a second in Europe and a few elsewhere. These are somewhat woodpecker-like, but more agile, perching up on their feet with bodies and tails held well clear; they can descend head-first and hang upside down beneath twigs and branches. The UK species is a woodland bird, always associated with trees or tall bushes. It has the unique habit in the UK of plastering mud around the entrance to its nest hole.
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Treecreepers
One UK species, with a second from Europe a very rare visitor; several other species worldwide. The two European treecreepers are exceptionally difficult to tell apart except by their calls and songs. They are mottled brown above, white or whitish beneath, and have stiff tails, used in the manner of woodpeckers’ as support when climbing, and large feet with sharp, arched claws. Their bills are curved and sharp, for extracting insect food and seeds from crevices in tree bark.
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Text (c) RSPB, used with permission