Casu marzu (also called casu modde, casu cundídu, casu fràzigu in Sardinian, or in Italian formaggio marcio, "rotten cheese",) is a traditional Sardinian sheep milk cheese, notable for containing live insect larvae (maggots). Although found mostly in the island of Sardinia, the cheese is also found in the nearby Corsica, where it goes by the name of casgiu merzu.