From
韩愈《
调张籍》(Han Yu, 'Teasing Zhang Ji,' middle Tang, c. 810 CE):
蚍蜉撼大树,
可笑不自量 (An ant tries to shake a great tree — laughable, not knowing its own measure). Han Yu wrote it defending the greatness of Li Bai and Du Fu against petty detractors. The image gave Chinese the idiom
蚍蜉撼树.