
Pigs, also called hogs or swine, are ungulates which have been domesticated as sources of food, leather, and similar products since ancient times. More recently, they have been involved in biomedical research and treatments, especially for their eyes and hearts, which closely resemble those of humans. Their long association with humans has led to their considerable representation in cultural milieux from paintings to proverbs. There are 2 billion pigs on the planet.
Native to Eurasia, they are collectively grouped under the genus Sus within the Suidae family. Despite pigs' reputation for gluttony, and another reputation for dirtiness, a lesser known quality is their intelligence. The nearest living relatives of the swine family are the peccaries.
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