Perry's Index to the Aesopica
Fables exist in many versions; here is one version in English:
THE SNAKE, THE WEASEL AND THE MICE
A snake and a weasel were fighting with one another inside a house. The mice
who lived in the house were always being hunted down by either the snake or
the weasel, so when they saw the snake and the weasel fighting with each other,
they emerged from their holes and scurried around. When the weasel and the snake
saw what was happening, they stopped fighting with each other and turned their
attention to the mice.
The same is true in a city: if you recklessly get involved in a political
dispute, you will become an incidental casualty of the quarrel.
Aesop's Fables. A new translation by Laura
Oxford University Press (World's Classics): Oxford, 2002.
cover, with new ISBN, published in 2008; contents of book unchanged.
Perry 197: Gibbs (Oxford) 63 [English]
Perry 197: Chambry 289 [Greek]
You can find a compilation of Perry's index to the Aesopica in the gigantic appendix to his
edition of Babrius and Phaedrus for the Loeb Classical Library
(Harvard University Press: Cambridge, 1965). This book is an absolute must for anyone interested
in the Aesopic fable tradition. Invaluable.