Actually, this is not a piece of fancy – there are some mouse species which sing, notably Alston’s Brown Mouse (Scotinomys teguina), found in Central America. Perhaps this one stowed away aboard a ship that landed at Dover!
“In our journal of May 4th, 1844*, we recorded the capture of a singing mouse, which was exhibited at the Exchange public house Charlton; and we have now to record that a similar lusus naturae# has been caught at the residence of a laboring man named Samuelson, living in Strond-lane, Dover. It appears tha the family have for the past 3 months heard a chirping behind the fire-place, which was supposed to be from a cricket. The gude wife, however, one evening saw a mouse run into a hole, and at night set up a live trap: in the morning she was much surprised at hearing a singing noise proceed from the trap in which the mouse was caught. It was then transferred to a more roomy cage, and has since daily amused numbers who have been to visit this musical genius, which at times sings very loud, and much like a bird. The animal is very similar to the common mouse, except that the tail is much longer, and the head smaller, with very sharp eyes.” – Dover Telegraph.
The Stamford Mercury, 8th January, 1847.
*i.e. in The Dover Telegraph.
#Freak of nature.