Love Is in the Air—Even If You Can't Quite Hear It
I heard it on the radio late one night, just as I was drifting off. The news came in on the lips of a BBC reporter, through the salt spray of an impending dream. Mice can sing. To one another, when they want to mate. You can't hear it, the reporter said.
But now I was awake, I was floating. They sing! Even though you can't hear it—you can only hear them skittering across your kitchen counter on winter nights, leaving tiny black, perfectly formed pellets in your fruit bowl.
What do they sing? Can birds hear it, and does it make them cock their heads in the early morning, just before dawn? Is it operatic, what the mice sing, a full-throated invitation to couple madly on your kitchen floor? Is it a love duet, a trilling affirmation of consensual desire? Do they nibble on a pear while they're singing, and does the soft fruit moisten their palates and put them in robust voice? Do girl mice sing, too, or do they lick their whiskers and wait?
I checked the local newspaper in the morning. There was a small item in the Lifestyle section:
"Scientists have long known that male lab mice produce high-frequency sounds—undetectable by human ears—when they pick up the scent of a female mouse… Audio recordings of the sounds, modified for human ears, reveal that the vocalizations are patterned songs, not random twittering…"
How long have scientists known? While the rest of us were marveling over whale songs, were scientists coyly bobbing their heads to modified mouse ditties? After they finally gave up on the music of the spheres, did they start randomly listening to the least vocally flamboyant of creatures? What if the expression "quiet as a mouse" set off a chain reaction of urgent questions, jotted in notebooks in the dead of night?
I turned to Google. "Mice can sing," I typed, and there arose a chorus of affirmations. "Picking Out the Faint Notes of Die Fleder-Mouse" headlined an article at Canada's GlobeandMail.com. "Romantic Rodents Give Secret Serenades" led off a jaunty piece from NewScientist.com. And, darkly, from someone at the white nationalist Stormfront.org, a posting that read, "This is of limited use to the cause…, but I cannot be alone in feeling that it is obscurely encouraging."
I hurried on, arriving at last at an online journal from the Public Library of Science. And there it was, the report from a team of researchers at the Washington University School of Medicine in St. Louis, Missouri. It turned out that "Ultrasonic Songs of Male Mice" was number one in the journal's top 10 articles viewed within the past week, besting "First Observation of Tool Use in Wild Gorillas" (No. 2) and "Cro-Magnons Conquered Europe, but Left Neanderthals Alone" (No. 5), an event apparently auguring a global peace that so far has not materialized.
Still, mice can sing. Or so posit Timothy E. Holy, PhD, and his co-author, Zhongsheng Guo, who, like many scientists before them, began their experiment by dipping cotton swabs into mouse urine. They wanted to study how male mice responded vocally to the intoxicating scent of females. The mice were obliging, crooning into the mike placed inside their test chamber, and Holy's team was listening hard. But how could their indelicate human membranes pick up signals meant only for the quivery ears of a female rodent? Unless the scientists took the recording they had made and processed it on a computer, slowing down the audio track and dropping the pitch so the mouse sounds would be audible to the human ear…
Moments of inspiration can come quietly, even casually. When they slowed the mouse sounds, Timothy Holy later wrote, they heard something unusual, "like a series of breathy whistles," and when they dropped the pitch several octaves, they didn't hear grunts or whines or frantic yodels of lust. They heard something wonderfully like music. A melodic trilling. A rhythmic thrumming. An ultrasonic welcome to the dance of life.
"There was joy in this discovery," Holy told Associated Press reporter Cheryl Wittenauer. "We didn't expect it." And yet, and yet...he was ready to hear something. Imagine a darkened room, the needle poised above the vinyl record, silence about to give way to exquisite sound. Think of a hushed opera house, where not a creature is stirring as the tenor gathers his breath. "The first moment I heard them," Holy told the British newspaper The Guardian, "I thought they sounded like songs, and they really do." He listened to one mouse, then another and another. All their songs were different. Were some better than others? Did the Pavarotti of rodents always get the girl? Holy didn't know. "Whether a male gains an advantage when it comes to mating by singing well is something nobody has yet looked at," he said. Was there a twinkle in his eye when he said it? Will the rewards of scientific inquiry never end?
I had to hear the music. And I could— there were actually links in the online research paper. I just needed to click once, twice with my...well, my mouse...and the computer would download two tracks. The first one would play the mouse opus four octaves lower than the mouse had actually performed it, but just as fast. The second track would play it lower, too, but 16 times more slowly, an adagio for mice and men.
I clicked on the first track, and into my waiting ear came a sweet and silvery warbling, a delicately insistent twitter, a refreshing spritz of sound. It was beautiful. It was endearing. It was relaxing, though it made my neutered Labrador hide beneath the desk, and my black cat look up from snoozing and primly lick her lips.
I clicked on the second track. It began with a long slow stroke, then a shorter one, and then a glide and a swoop, with intriguing variations in timbre. It was rich, it was undulating. It was melancholy, too, but under that was something, oh, sweet and resonant, like the last drop of wine decanted straight to the back of the throat. It was desire under the floorboards, everywhere and nowhere. It was mousy me afloat in my bed, under a night sky scurrying with stars.