The idiom 鹬蚌相争 (the snipe and the clam wrestle each other) uses 蚌 to describe two sides fighting while a third party reaps the benefit.
usage
Read bàng for the mollusc sense. A separate reading bèng appears only in the place name 蚌埠 (a city in Anhui), which also drives the internet phrase 蚌埠住了 (a pun on 绷不住了, 'can't hold it in').
Left insect radical. In Chinese taxonomy 虫 covers far more than insects: snakes, frogs, shellfish, all small wet creatures. It marks 蚌 as a mollusc, the freshwater clam. Family: 蛤, 蚝, 蛇.
Right 丰 supplies the sound, drifting from fēng to bàng through labial alternation. It is a pure phonetic; the idiom 鹬蚌相争 keeps this character in modern use.
