Sources : Bat

Ovid [1st century CE] (The Metamorphosis, Book 4, 389): While they seek the shadows, a thin membrane stretches over their slender limbs, and delicate wings enfold their arms. The darkness prevents them knowing how they have lost their former shape. They do not rise on soft plumage, but lift themselves on semi-transparent wings, and trying to speak emit the tiniest squeak, as befits their bodies, and tell their grief in faint shrieks. They frequent rafters, rather than woods, and, hating the light, they fly at night, and derive their name, ‘vespertiliones’, from ‘vesper’, the evening. - [Kline translation]

Pliny the Elder [1st century CE] (Natural History, Book 10, 81): The bat is the only flying creature that bears live young and feeds them with its milk; it also carries its children in its arms as it flies.

Saint Ambrose [4th century CE] (Hexameron, Book 5, chapter 24.87): The bat is an ignoble creature, whose name is taken from the word for evening. They are equipped with wings, but at the same time they are quadrupeds. They are provided with teeth, in this respect differing generally from other birds. As a quadruped, too, the female brings forth her young alive and not in the oval stage. Bats fly in the air like birds but prefer to be shrouded in the dusk of evening. In flight they do not use the support of wings but rely on their webbed feet which serve as wings, both as a balance and as a means of propulsion. These common creatures have this faculty, too, of adhering one to another, assuming any position like a pendant bunch of grapes, so that, if the lowest in place gives way they all fall apart. - [Savage translation, 1961]

Isidore of Seville [7th century CE] (Etymologies, Book 12, 7:36): The bat (vespertilio) takes its name from the time of day, because it avoids the light and flies around in the dusk of evening (vespertinus), making darting movements and supported by delicate arm-like limbs. It is an animal similar to a mouse, producing not so much a call as a squeak. In appearance it is a quadruped at the same time as being equipped to fly; this is not usually found among other birds. - [Barney, Lewis, et. al. translation]