My cat does this as well when a bird is close by.....they think they are going native with the lingo. Unless he is taking a course on the internet while I am out, my bird is just pretending to speak beak talk.
acorn - fruit of the oak tree: a smooth thin-walled nut in a woody cup-shaped base. acorn cup, cupule - cup-shaped structure of hardened bracts at the base of an acorn. oak tree, oak - a deciduous tree of the genus Quercus; has acorns and lobed leaves; great oaks grow from little acorns. fruit - the ripened reproductive body of a seed plant.
Symbolism Wiki. Acorn. The acorn is the seed of the mighty oak tree; therefore, it symbolizes potential and strength. The strongest oak of the forest is not the one that is protected from the storm and hidden from the sun. It's the one that stands in the open where it is compelled to struggle for existence against the winds and rains and the scorching sun. - Napoleon Hill.