The drugs raid was going well. Over 700 illegal cannabis plants had been found at the farm in Reggio Calabria, and now the search was being extended to nearby buildings. Suddenly, the police stumbled on an extraordinary find: not guns, not bundles of stolen banknotes, but...cages full of dormice.

The small rodents are a favourite food of the 'Ndrangheta, a Mafia clan based in southern Italy. One of the world's richest criminal gangs, they have made a fortune smuggling drugs to Europe from Latin America and Africa.

"When the police listened to Mafia phone calls during investigations into drug trafficking, they learned that after disputes between clans they have peace-making dinners where they eat dormice," explains Giovanni Malara, founder of anti-poaching group, Gruppo Adorno.

Dormice have been eaten in Italy since Roman times. Stuffed with pork mince and baked, they were regarded as a rare delicacy. Now protected by law as an endangered species, they are still served up secretly in some restaurants.

The Mafia are not alone in thinking that important occasions should be marked by eating special food. Among those recorded by historians is the wedding of Henry IV, king of France, to Marie de MediciA member of a wealthy Italian family, she ruled France as regent for her son Louis XIII following her husband's assassination in 1610. in 1600. Held in Florence, it involved a banquet of more than 50 courses. In 1817, George IV gave a 27-course dinner for Grand Duke Nicholas of Russia at Brighton PavilionA splendid building with an interior influenced by Islamic and Chinese architecture., at which the piece de resistanceA French phrase meaning a masterpiece or outstanding object. was a four-foot-high Turkish mosque made entirely of marzipan.

Many of the dishes regarded as delicacies in other ages, and by other cultures, can seem completely revolting to us. Other Roman treats included garum, a sauce made from fish intestines steeped in salt. At royal banquets in China, raw monkeys' brains were served. Roasted cats, peacocks cooked in their feathers and pies filled with live frogs featured in Medieval feasts.

The city of MalmoA coastal city in the west of Sweden. even has a Disgusting Food Museum, with 85 nauseating dishes on display from 30 countries. They include kungu cake, a pudding made from hundreds of crushed flies; fried locusts; and a drink made from frogs and quails' eggs.

After touring the museum, you are invited to taste a dozen of the exhibits. One visiting journalist, Arthur De Meyer, threw up ten times. Among the dishes he tried was durian, a spiky, custard-like fruit from Southeast Asia, which he said "smelled like socks at the bottom of a gym locker, drizzled with paint thinner."

Another was hakarl, an Icelandic dish made from shark. Eating it, he said, "was like gnawing on three-week-old cheese from the garbage."

But the fact that these dishes survive at all indicates that some people are happy to tuck into them. In CambodiaA country in South East Asia bordered by Thailand, Vietnam and Laos., fried tarantulas were first eaten in desperation by starving people under the Khmer RougeA murderous left-wing political party which ruled Cambodia from 1975 to 1979., but went on to become a popular snack.

Some say, yes. There are lots of things we refuse to eat because we think they look disgusting, but which we might find delicious if we ate them blindfolded. The very fact that some people like what others consider revolting shows that no food is intrinsically nice or nasty. Just as Europeans consider some Asian dishes weird, many Asians are horrified by the idea of eating pizza.

Others argue that disgust is an instinctive physical reaction which prevents us from eating harmful food. If some dishes are enjoyed in some parts of the world but not in others, it is because different cultures have different levels of tolerance. There are some things that no one would eat unless they were absolutely desperate - and even then they would probably be sick.