I’ve been looking into the word “pest”, and the dictionary showed me 害虫, but 虫 means insects, so I wonder whether the word 害虫 only means harmful insects or it also can be used to refer to other pests like snakes or rats?
害虫 and 益虫 can only refer to insects, animals like snakes or rats can be called 有害动物。
But nowadays terms like 害虫 or 有害动物 are getting less and less use.
- 虫 means the insect. one kind of it is 害虫， pest in English
- In Chinese, especially in some dialects, 虫 also was extended to other animals, for example, 长虫==蛇(snake）， 大虫==老虎(tiger). These extension cases are few.
- sometimes 害虫 also refers to some bad persons who harm the society
昆虫 means insects. 虫 does not mean insects.
虫 means worms, and the meaning is roughly extended to creepy-crawlies, and is sometimes even extended to small animals, including insects, snakes, crabs, shrimps, tadpoles, frogs, clams, etc.
In ancient China, all the animals were classified into four categories, namely 虫鱼鸟兽, where small animals except fishes and birds were in the 虫 category.