- [Narrator] On the Italian island of Sardinia,

there's a delicacy that has been consumed

for thousands of years.

It is known as the world's most dangerous cheese.

Yeah, you heard right.

(mellow music)

Meet Simone Ibba, a third generation sheep farmer.

- [Narrator] Casu marzu literally means rotten cheese,

and it's not for the faint of heart,

because this cheese is infested

with thousands of live maggots.

And while that might seem a bit off-putting at first,

it's the maggots that give the cheese

its distinctive texture and flavor.

Here's how it works.

First, a traditional wheel of pecorino cheese

is made from sheep's milk.

Then a special fly called a cheese fly

is allowed to lay its eggs in it.

- [Narrator] Over the course of two to three months,

the maggots eat the cheese, and then excrete it out again,

transforming it into the soft and creamy casu marzu.

- [Narrator] Today, it's a favorite for special occasions,

like weddings and birthday parties.

But eating this cheese can be dangerous.

- [Narrator] Even though cases like this are extremely rare,

it's risky enough that the cheese is illegal to sell.

But farmers like Simone continue to make it for themselves.

- [Narrator] And they just can't get enough.