Jazzoctopus wonders why
the Spanish would use a more subtle feature of the bat to make it's name - "blind mouse" rather than "flying mouse"I think I may safely say that we are not really aware that we are talking about "blind" mice. Nowadays, "murciélago" doesn't give away its etymology so easily. For one thing, the consonantal change makes it more difficult to relate "ciélago" to our word for "blind", which is just "ciego". More importantly, though, our contemporary word for "mouse" has nothing to do with the Latin "mus/muris"!!
Spanish mice are always "ratones".
As to how the ancient speakers of Latin knew that bats were blind or nearly, I seem to remember that there are some types that don't even have eyes?? That would be a definite sign. Also the fact that they were nocturnal, and possibly the way they fly around, almost crashing into objects and then deftly avoiding them at the last moment when they detect them.
