燕子衔泥垒大窝 (燕子銜泥壘大窩) yànzi xián ní lěi dà wō

yànzi xián ní lěi dà wō phrase the swallow's nest is built one beakful of mud at a time; many a little makes a mickle
Domain: Proverb 谚语
Notes: (CC-CEDICT '燕子銜泥壘大窩')