Little pitchers have long ears. Little folk or children hear what is said when you little think it. The ear of a pitcher is the handle, made in the shape of a man's ear. The handle of a cream-ewer and of other small jugs is quite out of proportion to the size of the vessel, compared with the handles of large jars.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
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