The Linnet's Tale, Dale C. Willard
This should be loathsomely sweet, but it wasn't. It's about an
anthropomorphized colony of mice and how they react to the arrival of a
barn cat, and it's told by an adopted orphan linnet. It's charming because
the characters would be charming if human - more than a bit
Cranford - the alterations of style and society to fit mice are
coherent, and it's a real plot, because it's quite clear that death is real.
So wrote clew in
Fiction (20th c.).