燕子銜泥壘大窩 [－－衔－垒－窝]

Jyutping jin3 zi2 haam4 nai4 leoi5 daai6 wo1
Pinyin yàn zi xián ní lěi dà wō

Definitions (CC-CEDICT)
  1. the swallow's nest is built one beakful of mud at a time (idiom)
  2. many a little makes a mickle