A truffle hog is any domestic pig used for locating and extracting the fruit bodies of the fungi known as truffles from temperate forests in Europe and North America. Pigs have an exceptional sense of smell, and are able to identify truffles as deep as three feet underground. It was thought that the natural sex hormone androstenol of the male pig, which is also found in truffles, was responsible for this ability;[1] however this has been proven false, as the molecule dimethyl sulphide was shown to signal instead.[2] Pigs also have a natural affinity for rooting in the earth for food. They are trained to hunt truffles by walking on a leash through suitable groves with a keeper.[3]
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