Fearing that one of the canaries had perhaps hurt its wing and had been unable to get out of the storeroom before it was closed, Mrs. Cahall entered and switched on the light—what she saw sent her running into the living room shouting to her husband to “come and see mice—three of them—that sing like canaries, nibbling at one of the seed sacks.” Doctor Cahall laughed. “Impossible,” he said. When she returned with her husband the mice, frightened, had disappeared. Doctor Cahall enjoyed his joke—but not for long.
The next evening, at about the same time, the singing was heard again. This time Doctor Cahall saw the mice: a little one with a shrill, melodious “soprano,” a medium-sized mouse with (shades of the three bears) a medium-sized voice, and a big fat one with a deep “chirrup.”
These mice have continued to provide the Cahall’s with entertainment.
They form a trio and harmonize rather well. As they are quite wild and shy, you must crouch in the dark storeroom to hear them. When the light is flashed on they soon run to cover, usually, however, continuing their song in flight. The little soprano is the most proficient of the three, Mrs. Cahall asserts, and is also the most persistent. Sometimes, unaccompanied by her “supporting cast,” she will give solos while on a solitary forage in the storeroom.
“I say ‘she’ because the little mouse seems like a female,” explained Mrs. Cahall. “Although she is the tamest of the three, I have not succeeded in getting on sufficiently good terms with her to examine her very closely. But I am making progress. Just the other night I got her to eat a bit of cheese out of my hand. I want her to get accustomed to the smell of my hand and to associate it with food. In this way I hope gradually to tame all three mice and add them to my pet collection.”
The three songsters have all the physical characteristics of the common house mouse. They are steel grey in color. When singing they often sit upright on their haunches, place their fore-feet about their heads and twitter in their respective keys very much in the attitude of dogs baying at the moon.
Mrs. Cahall says that she has every reason to believe that these songs are not indications of impaired breathing or of a diseased condition of the vocal chords. Her opinion is that the mice sing because they want to, and that, if the song means anything at all, it means that the mice are enjoying themselves. She bases this assumption on the fact that the songs are usually forthcoming at feeding time.
Just why the mice did sing was indeed puzzling. The writer made the tentative suggestion that they might have learned the habit from the canaries. This, Mrs. Cahall doubted, since the mice never sang in the daytime when the canaries were singing, and could scarcely be expected to wait modestly until their unwitting instructors had gone to roost before piping their soft-toned imitations.
Nor does one find any support of the “imitation theory” among the papers of Prof. Lee R. Dice of Michigan, who has done considerable laboratory experimentation with singing mice. Not only is Prof. Dice skeptical of the idea that singing mice imitate birds but he doubts that any musical sounds influence them very much. Says Prof. Dice: “. . . the captive male [singing mouse] in my possession did not respond in any way to musical sounds of many different sorts produced for his benefit by the phonograph and by various instruments. This does not agree with the observation of Brehm who states that singing mice are stimulated to sing by piano music.”
Despite exhaustive research on the subject, Prof. Dice does not make a definite statement as to the cause of the rare occurrence of a musical song in certain otherwise normal house mice.