What are the proper names for rats and mice? - briefly
The standard scientific name for the common brown rat is Rattus norvegicus, and the house mouse is Mus musculus. In everyday English the species are simply called “rat” and “mouse,” respectively.
What are the proper names for rats and mice? - in detail
Rats and mice are distinct taxa within the order Rodentia. The generic name for the true rat is Rattus, while the generic name for the true mouse is Mus. In scientific literature, species are identified by binomial nomenclature, for example Rattus norvegicus (the brown or Norway rat) and Mus musculus (the common house mouse).
Common English names vary by region and context. “Rat” typically denotes larger members of Rattus and related genera, such as the black rat (Rattus rattus) and the roof rat (Rattus rattus). “Mouse” refers to smaller rodents, primarily Mus species, but also includes field mice (Apodemus spp.) and deer mice (Peromyscus maniculatus). In the pet trade, “fancy rat” and “fancy mouse” identify domesticated varieties bred for coloration and temperament.
For practical identification, consider the following criteria:
- Size: rats exceed 20 cm body length (excluding tail); mice remain under 10 cm.
- Tail proportion: rat tails are thick and proportionally shorter; mouse tails are slender and often equal to body length.
- Ear size: rat ears are relatively small; mouse ears are large relative to head.
- Skull morphology: rat skulls display a more robust rostrum; mouse skulls are finer and more delicate.
In biomedical research, the term “laboratory rat” usually refers to Rattus norvegicus strains such as Sprague‑Dawley or Wistar, while “laboratory mouse” denotes Mus musculus strains including C57BL/6 and BALB/c. These designations are critical for reproducibility and regulatory documentation.
Culinary and pest‑control contexts employ the same scientific names to differentiate species. Food safety regulations list Rattus norvegicus and Rattus rattus as prohibited for human consumption in many jurisdictions, whereas Mus musculus may appear in certain traditional dishes under strict controls.
Accurate terminology therefore depends on taxonomic rank (genus, species), morphological traits, and the specific application—research, pet ownership, agriculture, or food industry. Using the precise scientific name eliminates ambiguity and aligns communication across disciplines.