larvæ

Their food is principally composed of nuts, but they also eat corn and grain, acorns and beech-nuts, whilst (possibly as a corrective to so much vegetable food) they will at times feed upon beetles, caterpillars, and other insects and their larvæ. The manner in which they obtain the kernel of the nut is very interesting. When a nut has been obtained, it is placed in a crevice of the bark of a tree, or in a crack or slit of a paling or gate-post, and by continuous knockings with its hard bill, by dint of perseverance the most stubborn shell is at length broken and the contents extracted. They, like squirrels, often lay up a stock of nuts for a possible "rainy day;" and if nuts be placed in suitable positions near their haunts, Nuthatches will often find them out, break the shells, and eat them. It is during this operation that they make the peculiar rapping noise that has so often attracted attention. The stroke of their bills against the hard shell of the nut can be heard upwards of two hundred yards away.

1901, W. Swaysland, “The Nuthatch”, in Familiar Wild Birds (Third Series, With Coloured Plates), Cassell and Company, pages 30-31