In the Middle Ages, the bat was understood to occupy an unusual position amongst animals. Ancient and medieval authors were well aware that while bats have wings and fly, like birds do, they also have teeth, give birth to live young, and produce milk—none of which are avian traits. Premodern taxonomies (systems of classification for living things) differed significantly from modern ones;1 the bat in the medieval period was often spoken of as a bird with some “quadruped” characteristics.2 For example, some twelfth-century bestiaries, drawing directly from Ambrose’s Hexameron (Book 5, 24.87), say:
The bat [vespertilio], an ignoble animal, takes its name from “evening” [vespere]. Moreover, it is both flying and a quadruped, and uses its teeth, which you may not be accustomed to finding in other birds. It gives birth like quadrupeds, not as eggs, but as living young.3

The bat’s liminal nature was fodder for medieval fables as well. The most popular medieval bat fable (or at least, the one extant in the greatest number of versions)4 was The Bat and the Birds (Perry Index 566). In this fable, a bat attempts to play both sides in a conflict between quadrupeds and birds, and is ultimately punished for his duplicity.
Ambiguity as Deceptive
A Latin verse version by medieval English author Alexander Neckam, who lived in the late twelfth to early thirteenth century, goes as follows:
De vespertilione et avibus
Quadrupedes et aves gererent dum bella furentes
et modo quadrupedes, nunc fugerent volucres,
versutus vespertilio se iunxit utrisque
ut, quicquid fieret, tutus untrinque foret.
Auribus et mammis se quadrupedem simulabat,
credi par alis alitibus poterat.
Hac se fraude tegens inter fera prelia tutus
fallebat stolidum cautus utrumque genus.
Ut fraus nota fuit, genus hunc abiecit utrumque
et merito placuit ut neutrum neutri.
Hac re quadrupedes et aves dum vespere pausant,
antique fraudis conscius ipse fugit.
Sic qui se fallax nunc his nunc ingerit illis,
omnibus ingratus, iure repulsus erit.5
My translation:
The Bat and the Birds
While the quadrupeds and birds were waging a furious war, and at times the quadrupeds were fleeing, at other times the birds, the cunning bat united himself to both, so that, whatever happened, he would be safe from both sides. He resembled the quadrupeds in his ears and teats, and could be taken for a bird because of his wings. So, deceptively hiding himself, safe amongst the fighting beasts, the cautious one tricked the foolish ones of both kinds. When the deceit was known, both kinds cast him out, and he deservedly was accepted by neither one nor the other. Because of this, when quadrupeds and birds rest in the evening, he, conscious of the earlier deception, flees. Thus, whichever deceitful one pushes himself onto first some, then onto others, will justly be rejected, unacceptable to all.
The bat in the fable of The Bat and the Birds values self-protection above “loyalty” to one party or another, and sits uneasily between categories. Neckam’s version construes his strategy as clever, but deceptive, and judges his ultimate status as an exile as well-deserved, and perhaps inevitable.

While Neckam’s moral is pretty general, moralizing the conflicting groups as “some” and “others” whom one shouldn’t act fickle towards, other medieval (and modern) moralists were more direct in casting the fable in political terms. William Caxton’s Aesop (1484) proclaims:
And therfore he that wylle serue two lordes contrary one to other may not be good ne trewe/ And they whiche relynquen and leue theyr owne lordes for to seruve another straunger/ whiche is enemy to theyr lord/ ben wel worthy to be punysshed/6
(And therefore, he that will serve two lords opposed to one another cannot be good or faithful. And those who abandon and leave their own lords to serve another foreigner who is enemy to their lord are well worthy to be punished.)
Eighteenth-century churchman Samuel Croxall, meanwhile, waxed fervent about deserters and traitors to one’s country:
For any one to desert the interest of his country, and turn renegado, either out of fear, or any prospect of advantage, is so notoriously vile and low, that it is no wonder if the man, who is determined in it, is for ever ashamed to see the sun, and to show himself in the eyes of those whose cause he has betrayed.7

The bat’s ambiguous nature does not jibe well with Caxton’s and Croxall’s denouncements, which compare him to someone who deserts their lord or betrays their country. Indeed, perhaps his nature, as the fables have it, does not jibe well with the genre’s broader tendency to naturalize and essentialize social categories, by using animals as metaphors for humans, as I have discussed in previous posts. Fables map species differences to human social differences, and in so doing, often portray these social differences as inherent and immutable—stark as the differences between a donkey and a lion, or a wolf and a sheep.
But, after all, which group should the bat try to belong to, in this fable? If he were to side only with the quadrupeds, the birds might deem him a traitor, and vice versa. His characteristics align him with both sides. In a sense, by allying with both sides at different points in time, he is being true to his own nature, which is ambiguous. This ambiguity can render him safer, but it can also render him more vulnerable.
Ambiguity as Adaptive
Another bat fable depicts the bat’s ambiguous characteristics as potentially adaptive in the face of danger, and indeed as something for humans to emulate. In the fable of The Bat and the Weasel (Perry Index 172), a bat is captured by a weasel and pleads for his life. The weasel insists that she cannot spare the bat, since she is the enemy of all winged creatures. Declaring that he is not a bird, but a mouse, the bat is freed.8 Then, he is caught by a second weasel, who claims to hate all mice. The bat now insists he is not a mouse, but a bat, and he is once again released. The conclusion: “The fable demonstrates that we too must not persist in the same devices, reckoning that those who adapt themselves to circumstances often escape dangers.”9

Together, these bat fables speak not only to the perceived ambiguity of the bat as a creature, but the perceived ambiguity of being ambiguous. Those who don’t fit into a single category can face mistrust and disapprobation, but that same liminality can also be a source of strength.
Linnet Heald
PhD in Medieval Studies
University of Notre Dame
- See Susan Crane, “A Taxonomy of Creatures in the Second-Family Bestiary,” in New Medieval Literatures vol. 10, issue 1 (2008), pp. 1-48, for an insightful analysis of medieval bestiary taxonomy, for instance. ↩︎
- Live birth and the production of milk are of course mammal traits, not quadruped traits per se. The taxonomic category of “mammals” was introduced by Carl Linnaeus in the eighteenth century, however, and would be anachronistic here. Interestingly, Linnaeus categorized both bats and humans as primates. ↩︎
- Vespertilio, animal ignobile, a vespere nomen accepit. Est autem volatile idemque quadrupes, et dentibus utitur, quos in aliis avibus reperire non soleas. Parit ut quadrupedia, non ova sed pullos viventes. Latin text from Willene B. Clark, A Medieval Book of Beasts: The Second-Family Bestiary (The Boydell Press, 2006), p. 182. Translations in this post are mine (unless otherwise stated). My own translation above differs little from Clark’s, but Clark notably translates ut quadrupedia as “like mammals.” ↩︎
- See Francisco Rodríguez Adrados, History of the Graeco-Latin Fable, vol.3 (Brill, 2003), p. 727. ↩︎
- Giovanni Garbugino, ed., Alessandro Neckam, Novus Aesopus, Favolisti latini medievali, vol. 2. (Università di Genova Facoltà di Lettere, 1987), p. 56. ↩︎
- R. T. Lenaghan, ed., Caxton’s Aesop, Edited with an Introduction and Notes (Harvard University Press, 1967), p. 107. ↩︎
- Samuel Croxall, Fables of Aesop and Others, Translated into English, with Instructive Applications, and One Hundred and Ninety-Eight Illustrations (Boston: T. O. H. P. Burnham, 1863), p. 229. ↩︎
- There is some slippage in terminology here—the bat didn’t deny he was winged, he denied he was a bird! However, this assertion satisfies the first captor. ↩︎
- I have epitomized L. Radif’s Italian translation, from Greek, of the fable’s narrative; the moral is, as Radif renders it, “La favola mostra che bisogna che anche noi non persistiamo negli stessi accorgimenti, calcolando che coloro che si adeguano alle circostanze spesso sfuggono ai pericoli.” L. Radif, “Il vespertilio protagonista di una favola di Alessandro Neckam,” Favolisti latini medievali e umanistici, vol. 7 (Università di Genova Facoltà di Lettere, 1998), p. 79. ↩︎


