all eyes and ears

Examples

• 1747 February, Viscount Ebrington (tr., ed.), the Père Girard (author), The Mother-Tongue: Or, Methodical Instruction in the Mother-Tongue in Schools and Families, John W. Parker, page 26, The volatility of children is proverbial: from the cradle their attention is attracted toward the visible objects around them, particularly towards those which shine or move, or emit sound. Thus they have accustomed themselves to be all eyes and ears; not indeed for the dumb language of a book, or for lessons which are often monotonous and unintelligible, but in order to see and hear whatever may stimulate their natural curiosity.
• 1759, Jaques Tristan (?) (tr., ed.), Marguerite Jeanne Cordier Staal (author), Memoirs of Madame De Stahl, page 219, “I am,” said I, “incensed against your Governor, for the Noise he made. Prisoners are all Eyes and Ears; though locked up, they come to the Knowledge of whatever passes: They hold that every little Motion concerns them, and trace it to the Bottom. [...]”
• 1798, Louis Augustin Guillaume Bosc (tr., ed.), Marie-Jeanne Roland (author), An Appeal to Impartial Posterity: By Madame Roland, Wife of the Minister of the Interior: Or, A Collection of Tracts, Written by Her During Her Confinement in the Prisons of the Abbey, and St. Pelagie, in Paris, Robert Wilson, volume 2, page 158, Seated by my mother, and keeping the silence that custom prescribes to young women, I was all eyes and ears; but when we chanced for a moment in private with Madam l’Epine, I asked her a few questions, the answers to which elucidated my observations.