The cheery “pleu, pleu, pleu” of the Yaffle as it flies from one tree to another may be heard in most parts of England and Wales, though in Scotland and Ireland it is almost unknown. It is a moderate-sized and somewhat ungainly bird in its actions, spending its life among trees, though it by no means restricts itself to woods, especially in autumn, when it may frequently be seen ascending some hedgerow tree, with its characteristic jerking motion, the stiff and pointed tail feathers aiding it to cling to the trunk. Its food consists of insects, more especially beetles and ants, which it finds in crevices of the bark, but it often descends to the ground in search of food.

Its flight is direct and undulating, and it proceeds by a series of rapid wing-beats followed by a short falling period, when the wings are half closed. On the ground it progresses by short hops, and when searching a tree for food, it ascends spirally from the base in short jerks, flying off when near the top to recommence its search at the base of another. Early in April it begins to excavate a nesting-hole, choosing for preference a tree destitute of lower branches. A neat circular hole is chiselled out, which is carried in horizontally for some distance, and then turns downwards. No special nest is made, the glossy white eggs, about five in number, being laid on the bare wood.

The young remain in the nest till they are full fledged, and then scatter to earn their own living.