Translation guide
The English word "pest" covers a wide range of annoying or harmful living things, from insects and rodents to troublesome people. In Japanese, there is no single perfect equivalent; the best translation depends on what kind of pest you mean.
Refers to insects that damage crops, infest homes, or bite/sting.
The standard word for harmful insects in agriculture, gardening, or household contexts. Literally 'harmful insect'.
この植物に害虫がついています。
This plant has pests on it.
農家は害虫駆除に苦労している。
Farmers struggle with pest control.
General word for insect or bug. In context, it can mean pest, especially when the harmful nature is clear.
台所に虫が出た。
There's a bug (pest) in the kitchen.
Technically means 'harmful animal' but sometimes used broadly for pests including larger insects or vermin. More common for mammals.
この地域では害獣による農作物の被害が深刻だ。
In this area, damage to crops by pests (animals/insects) is serious.
Refers to mice, rats, or other small animals that invade homes or damage property.
The standard term for harmful mammals like rats, mice, or raccoons. Often used in pest control contexts.
ネズミは代表的な害獣です。
Rats are a typical pest.
害獣駆除の専門業者を呼んだ。
I called a pest control specialist.
Specifically means rat or mouse. Use when the pest is clearly a rodent.
Refers to a person who is a nuisance, bothersome, or persistently irritating.
Literally 'troublesome person', a common way to call someone a pest or nuisance.
彼は職場の厄介者だ。
He's a pest at the workplace.
A person who causes trouble or annoyance. '迷惑' means nuisance or annoyance.
あの客は本当に迷惑な人だ。
That customer is a real pest.
Very casual and somewhat rude slang for an annoying person. 'うざい' means annoying/irritating, '奴' is a rough word for guy/person.
Use only among close friends; can be offensive.
あいつ、マジでうざい奴だな。
That guy is such a pest.
Refers to something (not necessarily living) that is a persistent annoyance.
A noun meaning trouble, annoyance, or nuisance. Often used in phrases like '迷惑をかける' (to cause trouble).
その騒音は本当に迷惑だ。
That noise is a real pest.
Literally 'seed of worry', meaning a persistent problem or annoyance.
この古いパソコンが悩みの種だ。
This old computer is a pest.
害虫 (gaichū) is for insects and similar small arthropods. 害獣 (gaijū) is for mammals and sometimes larger animals. In everyday conversation, people often just name the specific creature (e.g., ゴキブリ for cockroach, ネズミ for rat) rather than using the umbrella term.
Calling someone 害虫 or 害獣 would be extremely insulting and unnatural. Use 厄介者 or 迷惑な人 instead.
It seems there are pests (rats) in the attic.