Truffles, a delight of gourmets, are arguably the most prized edible fungi. Found mainly in western Europe, they grow near the roots of trees (particularly oak, but also chestnut, hazel, and beech) in open woodlands. Unlike typical mushrooms, truffles develop 3 to 12 inches (7.6–30.5 centimeters) underground, making them difficult to find. Truffle hunters use dogs and pigs that have been specially trained to find the flavorful morsels. Both animals have a keen sense of smell and are attracted to the strong, nutlike aroma of truffles. In fact, trained pigs are able to pick up the scent of a truffle from 20 feet (6.1 meters) away. After catching a whiff of a truffle’s scent, the animals rush to the origin of the aroma and quickly root out the precious prize. Once the truffle is found, the truffle hunter (referred to in French as a trufficulteur) carefully scrapes back the dirt to reveal the fungus. Truffles should not be touched by human skin, as doing so can cause the fungus to rot.