Pigs are a genus of even-toed ungulates within the family Suidae. The name hog most commonly refers to the domestic pig in everyday parlance, but technically encompasses several distinct species, including the wild boar. Swine is a collective noun generally used to describe pigs as a group rather than an individual, however it may often be implied in a pejorative manner to any living being expressing pig-like behavior. With around 2 billion on the planet, domestic pigs are also by far the most numerous pig species. Pigs are omnivores, and despite their reputation for gluttony, they are generally social and very intelligent animals.