The word chauve-souris is based on two words. The first, chauve, means “bald” and the second, souris, means “mouse”. This word is derived from calva sorex, literally “bald mouse”. However, this might be an alteration from cawa sorix, the “owl-mouse”. And it makes more sense as the owl, like the bat, is a nocturnal bird. And what about the word “mouse”? Well, it is a reference to the morphology of the bat.
