It's not that I don't like them. I love the way he can make one sentence last an entire page, range over several years, include brief biographies for several individuals and the background of an English/French peace negotiation, step its way down from one clause level to the next, up two, down three, up one, down one, up three, and end up with perfect clarity back where he started with a verb whose subject we haven't seen for 300 words or so. And it all makes sense, because Latin can do that (and modern English can't, which is why working out how to break those sentences down is probably the hardest part of translating). I love the mathematical precision and the sense of method underlying it all, a language which is a perfect construct for exactly this style of writing and not for, say, sending abusive text messages.
The problem comes when you combine this complexity with manuscript variations, and after two hours in the coffee shop this morning, this is the sentence that dealt the death blow to my brain for the day:
Item [Benedictus XI] restituit regem Franciae ad privilegia quae habuit prius a sede apostolica, quibus papa Bonifacius ipsum sicut filium ingratum privavit; et ipsum regem, non petentem, a >sententia [sententiis], >excommunicationum [excommunicationis], >[quibus?] ex praemissis [quibuscumque expressis] vel aliis causis >vinctum [ligatus erat [invitum?]], absolvit in hebdomada Pentecostes. Oh, I know what it says, that's not the problem. The difficulty is working out what's going on grammatically when you're trying to hold all the variants in your head at once. Clearly the starting point tomorrow is going to be writing that sentence out in all its possible permutations and translating it sans s and >s and ?s, and only then debating the merits of the different variants.
So, in the absence of a functioning brain, I turned to investigating the history of the word "rat". According to Murimuth, when the Scots besieged Stirling in 1303, the English inside held out "viriliter" so long as they had food, though they were reduced to eating "equos, canes, coria, mures et ratos" - horses, dogs, leather, mice and rats. But no dictionary I consulted (the Oxford Latin dictionary, the Collins, or any of the online ones I sometimes use) listed "ratus" or "rattus" as a noun. Classical Latin for "rat" was the same word as they used for "mouse" (as is still the case in some modern languages, I believe). The word is "mus" (hence "mures" in the accusative plural), which I find inexplicably cute, but which fails to explain the last item on the Stirling menu.
Middle English has "ratte", and modern Italian has "ratto", so it wasn't too much of a leap to assume that a man writing in 14th-century England would use something like "ratus". The Middle English Dictionary has it derive from Old English "raet", and compares it to Old French "rat" or "rate" and Middle Latin "ratus". Old French borrowing from English (via Anglo-Norman?) would make a kind of sense, though it's not terribly convincing because the current of language-sharing usually ran in the other direction, but that wouldn't explain how Italian got hold of it. Unless, of course, it was a parallel development owing something to the continental Germanic languages which had also retained the same word - Italian and French have borrowed plenty from those.
The OED, which you always want to turn to last because it provides all the answers and takes the fun out of it, confirms all this, provides examples in everything from Old High German to Catalan, and adds:
It is uncertain whether the Latin and Romance words are cognate with the Germanic words, or whether they were borrowed from Germanic, or vice versa; in any case the ultimate origin is uncertain; perhaps imitative of the sound of gnawing. None of the Latin and Romance words is attested before the end of the first millennium, and the fact that the German word has not undergone the High German sound shift suggests that the Germanic group is also late (Middle High German ratz, ratze, German regional (chiefly southern) Ratz, Ratze are secondary, perhaps hypocoristic formations). The word was probably spread with the reintroduction of rats to Northern Europe during the Viking Age (for a discussion of the physical evidence compare P. L. Armitage in Antiquity 68 (1994) 231-40).And, for anyone who wants the vocab to threaten their enemies in Latin: "Hoc anno (1305) fuit tractus, suspensus, et decapitatus Willelmus Waleys apud Londonias" (8).
 (Adam Murimuth, Continuatio Chronicarum, ed. Edward Maunde Thompson, (London: Eyre and Spottiswoode, 1889). 6-7)
 Murimuth 5. Although one spoilsport manuscript has "porcos" instead of "ratos". I am retaining "ratos" because I think the scribe of the manuscript in question probably substituted a reading of a more expected word for a lesser - "r" could look like a short-stemmed "p", "a" could be read as "o" with a stroke above it to indicate a following "r" and "c" and "t" at this period were often written in such a way as to make them very difficult to distinguish from each other - just ask the Green Knight's alter ego. "Ratos" also makes more sense in context - this is a list of unappetising things that one never wants to be reduced to eating, and though, as a vegetarian, I'd personally include pigs in that list, I suspect Murimuth and his contemporaries wouldn't feel it had the same effect as rats.
 When Edward I returns the favour the next year, besieging the Scots now holding Stirling, we are told that he besieged it for twenty days and that in the end the Scots surrended and emerged "discalceati" - unshod. I think that's a lovely little emotive detail in an otherwise fairly straightforward description; and it hints that the Scots were reduced to a similar extremity as the English. Apparently they hadn't had the opportunity to restock the castle well enough to withstand a siege.