The idiom "small skill in carving insects" refers to insignificant skills or tricks. Used for others, it is derogatory, sometimes used for modesty.
"Carving insects" refers to writing calligraphy, and "insects" refers to insect books.
Insect book, also known as "Bird Book" and "Bird Book Seal", belongs to a special artistic font, which prevailed in southern countries such as Wu, Yue, Chu, Cai, Xu and Song from the middle and late Spring and Autumn Period to the Warring States Period.
The skill of carving insects, formerly known as carving insects and seal cutting, was written by Yang Xiong, a writer in the Western Han Dynasty. Someone asked me if I liked writing Fu when I was young, and replied: Yes, but that was just a skill of carving insects and cutting seals when I was a child, and I stopped writing it when I was an adult. Yang Xiong belittled "Carving Insects and Seal Carving" not because they are easy to learn, but because they are the most difficult to learn, but they have little practical effect.
Later, people described "carving insects" as "carving insects"