Apart from just using




Is there a way of differentiating between a mouse and a rat, perhaps by adding something to鼠{ねずみ}?

From this chinese.stackexchange it seems that in Chinese they tend not to distinguish, but the top answer suggests that

仓鼠 is a kind of pet(one of my friends raise two). Wiki tells me rat is "大家鼠" and "mouse" is “小鼠", but I and people around me don't care this.

Of course, in scientific circle, academical researchers will adopt the Binomial Nomenclature(in Chinese, 二名法) system to distinguish them.

Is it a similar situation in Japanese, where the average person would just use the loan words, or not bother making a distinction? If so then what would be the scientific name for mouse/rat in Japanese?


クマネズミ属{ぞく} is the Rattus genus, to which all "true" rats belong, whereas Mice belong to the ハツカネズミ属, or Mus genus. These genera are both subgroups to the sub-family ネズミ亜科{あか}, or Murinae.

Now, these are the scientific names, and luckily, in contrast to English, these scientific names are based on Japanese words, so they do make sense for common people. If you really need to distinguish between the two it depends on your situation. If you are just talking in general to common people, for rat you could either say ドブネズミ, or simply describe it でっかいネズミ, and for mouse you could say ハツカネズミ, or describe it ちっちゃくて可愛{かわい}いネズミ.

In a more scientific situation, or if you think that the other parties of the conversation know about rats and mice, then you should use the appropriate name for that particular species instead (if you have to distinguish between them), as the above mentioned ドブネズミ and ハツカネズミ are just typical examples of rats/mice, but not necessarily the particular species you saw/bought/whatever.


The word ラット usually refers to laboratory rats used in experiments, whereas the word ねずみ is used to refer to wild animals.

The term ねずみ doesn't distinguish between mice and rats.


There is no distinction between "rat" and "mouse" in Japanese.

For example, ハツカネズミ(二十日鼠)is one species of mouse. So someone may use it for the translation of "mouse," but it is not accurate.

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