Funnily enough, the legend of the bird that eats scraps of meat from the crocodile’s mouth is a fable that has refused to die, specifically because it sounds like it is “probably true”.
I mean, It Stands To Reason, right? It’s not asking for too much suspension of disbelief.
And yet centuries of ornithology have not produced any concrete evidence that there is a bird that enters crocodile’s mouths to eat. There are birds that will feed around basking crocodiles; there are birds that pick at wounds on large herbivores; but this specific legend has yet to be formally substantiated. So I won’t really bother talking about it.
… wait, you thought that was what I was going to talk about? No, let’s talk about mice eating iron, which might actually be more feasible! Let’s take a look at it and the next anecdote…
Now, if you subscribe to the theory that giant gold-digging ants were in fact marmots who dug gold up and brought it to the surface (Peissel, 1984), then the second one may be another expression of rodents as gold-diggers. Emphasis on the may. Without further evidence, this is no better than deducing that dinosaur fossils inspired griffins and dragons. It may just as easily represent a miner’s superstition that mice in mines might have possibly eaten some of their precious metal (Zucker, 2024).
But what about the Cypriot mice who eat iron? While both observations are about metal-eating mice, they seem to be otherwise unrelated.
The origin of the story of metal-eating mice, and a bunch of other swarming animals, appears to be a lost work by Theophrastus (Zucker, 2024). The story is repeated by Aelian (5.12)
In the island of Gyarus Aristotle says that there are Rats and that they actually eat iron ore. And Amyntas says that the Rats of Teredon (this is in Babylonia) adopt the same food. (Aelian, 1959, p. 307)
and by Pliny (8.43 and 8.82)
M. Varro informs us… that the inhabitants of Gyarus, one of the Cyclades, were driven away by mice… (Pliny, 1855, p. 295)
We are informed by Theophrastus, that after the mice had driven the inhabitants of Gyara from their island, they even gnawed the iron; which they also do, by a kind of natural instinct, in the iron forges among the Chalybes. (Pliny, 1855, p. 350)
The anecdote of metal-eating mice as a historical event is also told by Antigonus, Heracleides, and Livy (Papademetriou, 1970).
First of all… where are they exactly? Cyprus and Gyaros are two very different islands. It appears likely that the Cyprus reading is a corruption in the existing manuscripts of the Marvelous Things Heard, where Γυάρῳ was misread as Κύπρῳ (Giacomelli, 2023). Indeed, a more recent translation of the Marvelous Things Heard gives this.
25 · It is said that in the island of Gyaros the mice eat iron. (Aristotle, 1984, p. 2783)
The distinction is important, because this is what Gyaros looks like.
It’s a barren, desert island in the Aegean, about 23 sq km in area, a far cry from populous Cyprus.
So… at face value, it would seem that this started out as a tale about how an island got overrun by mice who ate everything, which evolved into “mice eat iron on this island”.
I say seem because I’m just making up explanations after the fact, given what’s available. No better than using dinosaur fossils to explain belief in dragons.
… but wait, there’s more. You didn’t think there was more?
“Where mice eat iron” exists on its own as an expression. It was used, for instance, by Herodas.
But you’re a bad boy, Kottalos, so bad that none could find a good word for you even were he selling you, not even in the land where mice throughout eat iron. (Herodas, 1922, p. 115)
In other words, “you’re so worthless that, even in the places where they’re desperate, nobody would want you”. “Mice eating iron” here suggests hardship and scarcity. Perhaps the mice ate everything on the island and, having exhausted all available food, had nothing left to gnaw but iron?
However! It has been suggested that “where mice throughout eat iron” is a misreading, and it would be more correct as “where mice eat iron just as slag [i.e. metallurgical waste]”. The sense of the sentence would be the same (a place with low standards) but it would imply that “mice eating iron” is to be taken as something that happens quite often (Stamoulakis, 2023). In fact, mice chewing on metal didn’t just happen on Gyaros. It was seen as a portent of war at Lanuvium when the mice gnawed on metal shields, since they would soon be reduced to famine as a result of the war (Marcovich, 1977).
Which adds another dimension to metal-eating mice: that of something extraordinary happening. A place where mice eat iron is a place where the unexpected happens, for better or worse (Papademetriou, 1970).
On the other hand, Seneca uses the expression to describe Hades. Here, Hercules addresses Claudius in the ever-delightfully-named Apocolocyntosis*.
Listen to me and stop talking nonsense. You have come to a place where the mice gnaw iron [ubi mures ferrum rodunt]. Tell me the truth, quick, or I’ll knock the silliness out of you. (Seneca, 1902, p. 140)
Here, it reflects how tough and strenuous life is in Hades, although another commentator has suggested that it is a metaphor for a mouse getting caught in a trap (Ball, 1902). Perhaps it’s saying that this is a miraculous place where the impossible happens (Papademetriou, 1970). Or maybe it’s just trying to say that even the mice in Hades are so tough that they chew on metal (Marcovich, 1977).
Making them the equivalent of this guy, really.
But the most likely reason is to indicate scarcity and to criticize Claudius’ lavish lifestyle, which Seneca disapproved of. Like in the example of Lanuvium mentioned previously, the mice in the afterlife are starving, and soon Claudius will too - a terrible fate for the gluttonous emperor (Marcovich, 1977).
Finally, metal-eating mice (as a symbol for scarcity or marvelousness) eventually evolved into the modern Greek proverb “the fly is eating metal” (Papademetriou, 1970).
Ultimately, we need to ask the big question implied by all of this.
Iron is a 4 on the Mohs hardness scale. Mouse teeth are 5.5. Metal generally keeps mice away, but perhaps a sufficiently determined mouse - a starving one perhaps - could leave some gnaw marks on iron (Zucker, 2024).
So… perhaps there is some truth to it after all.
Aelian, Scholfield, A. F. trans. (1959). On the Characteristics of Animals, vol. I. Harvard University Press.
Aristotle, Barnes, J. ed. (1984). The complete works of Aristotle: The revised Oxford translation (one-volume digital edition). Princeton University Press.
Giacomelli, C. (2023). Suspicious toponyms in the De mirabilibus auscultationibus: Textual problems,“ forgeries,” and methodological issues. In Historiography and Mythography in the Aristotelian Mirabilia (pp. 234-257). Routledge.
Herodas, Headlam, W., & Knox, A. D. eds. (1922). The Mimes and Fragments. Cambridge University Press.
Marcovich, M. (1977). UBI MURES FERRUM RODUNT (Seneca,“ Apocolocyntosis” 7.1). Rheinisches Museum für Philologie, 120(H. 1), 85-89.
Papademetriou, J. T. (1970). The Mutations of an Ancient Greek Proverb. Revue des Études Grecques, 94-105.
Peissel, M. (1984). The Ants’ Gold. Harvill Press.
Pliny, Bostock, J. & Riley, H. T. eds. (1855). The natural history of Pliny, vol. II. Henry G. Bohn.
Seneca, Ball, A. P. trans. (1902). The satire of Seneca on the apotheosis of Claudius. Columbia University Press.
Stamoulakis, I. P. (2023). A Critical and Interpretative Proposal on Herodas 3, 75–76. Arctos–Acta Philologica Fennica, 57, 217-228.
Zucker, A. (2024). De mirabilibus auscultationibus 23–28 and Theophrastus’ Lost On Animals That Appear in Swarms 1. In The Aristotelian Mirabilia and Early Peripatetic Natural Science (pp. 86-111). Routledge.
