蚍蜉撼大树

pí fú hàn dà shù

lit. an ant trying to shake a big tree (idiom)

fig. to overrate one's own strength; also written 蚍蜉撼樹|蚍蜉撼树[pi2 fu2 han4 shu4]

蚍

pí

used in 蚍蜉[pi2 fu2]

蜉

fú

used in 蚍蜉[pi2 fu2]

撼

hàn

to shake

大

dà

big; large; great

树

shù

tree