Pigs are among the most versatile animals humans have domesticated. We keep them as pets, certainly, but we also eat them and use them to make leather and lots more. Often we think of them as hungry, dirty and not particularly bright. While it's true pigs will eat just about anything, the rest of our perceptions aren't entirely accurate. Here are some surprising, fun facts about pigs.
1. We domesticated pigs at 2 different times in 2 different places
Perhaps we recognized pigs' utility early on since two different cultures thousands of miles apart domesticated wild pigs, or boars. Near what is now modern-day Turkey, settlers domesticated wild boars that came to their villages for scraps of food about 10,000 years ago. Research also indicates that around 8,000 years ago, wild pigs were domesticated in China's Mekong Valley.
2. Pigs developed a dirty reputation
Despite their domestication and usefulness, pigs fell out of favor to a certain degree by B.C. 1,000. The Old Testament, specifically the Book of Leviticus, deemed pigs "unclean" and forbade the consumption of pig productions. The Koran followed suit in the 7th century A.D. While theories abound as to why pigs were held in low esteem, the likeliest reason is that pigs are happy to consume just about anything, including decaying flesh and feces, habits that made them unclean.
3. The pig holds a place in the Chinese zodiac
The pig is the 12th symbol in the 12-year cycle of the Chinese zodiac. It earned last place in the mythological race to determine each animal's place in the zodiac. The pig, having gotten hungry and then sleepy during the race, was the last to arrive at a meeting called by the Jade Emperor. Despite its latecomer status in folklore, people born in the year of the pig are considered to be good planners who work hard to achieve goals.
4. Pigs can save human lives
If you ever need a new heart valve, a pig may come to the rescue. Pigs' heart valves are used to make valves for humans. According to Harvard Health Publishing, these valves last around 15 years and typically don't require the use of anti-clotting drugs as mechanical valves do.
What's more, pigs are generally considered the best option for xenotransplantation, or organ transplants between humans and animals. They're just similar enough to us that their organs may work well in our bodies while still being different enough that a cross-species infection isn't as likely as it would be with other primates. However, more research is needed as trials have resulted in the rejection of some transplants.
5. Pigs don't really sweat
We use the phrase, "sweating like a pig," but the truth is pigs don't sweat a lot. Sweat is a way that warm-blooded animals keep cool, but they need functional sweat glands to do that. Pigs have the glands, but they don't work well. This is why pigs will roll around in mud, or even their own urine, to keep cool.
6. Pigs have crummy vision but a great sense of smell
Pigs can see things along the sides of their head — useful for spotting food, other pigs and potential predators — but they're not great at seeing what's right in front of them. They make up for this frontal vision lack with an excellent sniffer. They'll use their snouts to detect food, and thanks to a little extra muscle that gives it flexibility, the snout also can root out food.
7. Pig are intelligent, emotional creatures
A 2015 review of pig studies published in the International Journal of Comparative Psychology suggests that pigs have a complex psychology we're only now starting to understand. "Pigs display consistent behavioral and emotional characteristics that have been described variously as personality. e.g., coping styles, response types, temperament, and behavioral tendencies," the authors wrote.
The review also found that pigs respond to each other's emotions. "Emotional contagion in pigs involve[s] responses to other pigs' anticipation of positive or negative events, revealing the importance of social factors in emotion."