ハツカネズミ

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つ

か

ね

ず

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Meanings

1

noun

house mouse

usually written using kana alone

Refers specifically to the common house mouse (Mus musculus). In everyday Japanese, this is the standard term for the small rodent often found in homes.

台だい所どころでハツカネズミを見みつけた。

I found a house mouse in the kitchen.

ハツカネズミは実じっ験けん動どう物ぶつとしてよく使つかわれる。

House mice are often used as laboratory animals.

Kanji

二two, two radical (no. 7)
十ten
日day, sun, Japan
鼠rat, mouse, dark gray
廿twenty

Related words

鼠ねずみ
A general term for mice and rats. ハツカネズミ is a specific species, while 鼠 can refer to any small rodent.
ドブネズミ
Refers to the brown rat or Norway rat, a larger and more aggressive rodent commonly found in sewers and urban areas, unlike the small house mouse.

Written forms

ハツカネズミ
kana-only spelling
The katakana spelling is the most common written form for this animal name; usually written in kana.
二十日はつか鼠ねずみ
Kanji spelling is rare and may be encountered in older texts or for stylistic effect. The kanji literally mean 'twenty-day mouse', referring to its short gestation period.
廿はつ日か鼠ねずみ
out-dated kanji form
Contains the outdated kanji 廿 (twenty), which is rarely used in modern Japanese.

Etymology

The name ハツカネズミ (二十日鼠) literally means 'twenty-day mouse', likely referring to its short gestation period of about 20 days. The exact historical origin of the name is uncertain.