Why are they called rats? - briefly
The term originates from Old English ræt, borrowed from Latin rattus, which in turn stems from a Proto‑Indo‑European root meaning “gnawer” or “creeper.” Germanic languages such as Old Norse rottr reinforced the word, leading to the contemporary English designation.
Why are they called rats? - in detail
The name “rat” comes from Old English ræt, a term shared with Old Norse ratt and Old High German rat. Both derive from a Proto‑Germanic root rattaz, which in turn traces back to Latin rattus. Latin borrowed the word from an earlier Italic source, and the term entered French as rat before spreading throughout the Germanic languages.
When medieval scholars began classifying mammals, they assigned the genus Rattus to the larger, tail‑long rodents that differed from smaller mice. The scientific designation reinforced the common name, linking it to the Latin root.
Historical documents show the word used for pest species associated with grain stores and urban waste. During the 14th‑century plague outbreaks, chroniclers repeatedly referred to the animals as “rats,” cementing the association between the term and disease‑carrying rodents.
Key points of the etymology:
- Old English ræt → Middle English rat
- Old Norse ratt and Old High German rat share the same ancestor
- Latin rattus provides the classical foundation
- French rat transmits the word to later European languages
- Scientific genus Rattus formalizes the modern usage
Thus, the contemporary label originates from a Germanic‑Latin lexical chain, refined by medieval taxonomy and reinforced by the animal’s role in human environments.