The Chinese ideogram for family, household, or home 家 “Jia” consists of the signs for house, 宀, on top, and pig 豕, below. The reason “a pig in the house” came to signify home, household or family in China is explained by history.
In ancient China, pigs were regarded as intelligent animals, and their courage was admired. A folk rhyme from Northeastern China proclaims pigs to be the bravest animals, even braver than bears or tigers. According to an old Chinese proverb, it takes a lot of courage to hunt a tiger but to hunt a wild pig a coffin is also needed.
In other words, one’s life would be at stake. Unlike a hunted tiger or a bear, a hunted wild pig will not try to escape but will instead turn and attack the hunter. Due to their intelligence and instinctive recognition of traps, they were considered to be extremely dangerous opponents.
Moreover, the Chinese used to associate prosperity and money with pigs because, at least in the old days, only rich families were able to afford pork to eat. Since a large number of progeny was equated with “a lucky family life,” pigs with their large litters came to be regarded as a symbol of luck. “A pig in the house” 家 symbolized good luck in many respects since the Chinese desired nothing more for their families, households and homes.