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In 1877, Joseph Sidebotham, a Manchester cotton baron fascinated by natural history, published an informal correspondence in Nature describing how a mouse had serenaded him from the top of a woodpile. In the letter, Sidebotham notes that his son suggested that perhaps all mice can sing, but at frequencies that the human ear cannot hear, and that the audible mouse vocalist was an oddity (what today we would call a mutant).
Sidebotham dismissed his son’s idea, but it turned out to be right: mice do sing. In addition to the audible squeaks for which they are known, the rodents produce more-elaborate vocalizations reminiscent of birdsong, but at a frequency far beyond the limits of human hearing. In 2005, Timothy Holy, a neuroscientist at Washington University in St. Louis, and colleagues defined these ultrasonic vocalizations as songs using measures similar to those that researchers employ to distinguish songs from isolated calls in birds (PLOS Biol, 3:e386). “It was really when I wrote an algorithm that allowed me to shift the pitch of ...
