Casu marzu (also called casu modde, casu cundídu, casu fràzigu in Sardinian language, or in Italian formaggio marcio, "rotten cheese") is a traditional Sardinian sheep milk cheese, notable for containing live insect larvae. It is found almost exclusively in Sardinia, Italy.
Derived from Pecorino, casu marzu goes beyond typical fermentation to a stage most would consider decomposition, brought about by the digestive action of the larvae of the cheese fly Piophila casei. These larvae are deliberately introduced to the cheese, promoting an advanced level of fermentation and breaking down of ...