To hear, insects use diverse external structures, which transform acoustic signals to mechanical ones, coupled to astonishingly uniform mechanosensory transducers, the chordotonal organs. New evidence showing that chordotonal organs and vertebrate auditory hair cells are developmentally related and that chordotonal organs and insect bristle organs are mechanistically related suggests that all these ciliated mechanoreceptors may be derived from the same ancestral molecular mechanotransduction complex. Identification of these elusive molecules will settle this issue.