Practical Issues > Factory Farm Index> Pigs and Sheep

What the Experts Say

Professor Stanley Curtis of Penn State University found that pigs play and excel at joystick-controlled video games. He observed that they are "capable of abstract representation" and "are able to hold an icon in the mind and remember it at a later date." Professor Curtis says that "there is much more going on in terms of thinking and observing by these pigs than we would ever have guessed." Pigs are much smarter than dogs, according to the research, and even did better at video games than some primates. Says Dr. Sarah Boysen, Curtis� colleague, "[Pigs] are able to focus with an intensity I have never seen in a chimp."

Like us, pigs form close bonds. They like being scratched and, at the touch of your hand, will contentedly roll over for a belly rub. They also snuggle close to one another and prefer to sleep nose to nose.

Pigs form complex social units and learn from one another in ways previously observed exclusively among primates. For example, pigs use clever ploys to try to outsmart each other. Pigs often learn how to follow others to food before snatching it away. Those who are tricked learn to change their behavior in order to reduce the number of times they are deceived. And Dr. Mike Mendyl notes that pigs can signal their competitive strength and "use this information to minimize overt aggression during disputes about social ranks," just like many primates (including humans). He explains that "pigs can develop quite sophisticated social competitive behavior, similar to that seen in some primate species."

Pigs do not "eat like pigs" or "pig out." They prefer to eat slowly and savor their foods.

Pigs communicate constantly with one another. More than 20 of their oinks, grunts, and squeals have been identified for different situations, from wooing their mates to expressing, "I�m hungry!"

Pigs have a very long memory. Dr. Curtis put a ball, a Frisbee, and a dumbbell in front of several pigs and was able to teach them to jump over, sit next to, or fetch any of the objects when asked to and they could distinguish between the objects three years later.

Scientists at the University of Illinois have learned that not only do pigs have temperature preferences, they also will learn through trial and error how to turn on the heat in a cold barn if given the chance and turn it off again when they are too warm.

Professor Donald Broom of Cambridge University Veterinary School says, "[Pigs] have the cognitive ability to be quite sophisticated. Even more so than dogs and certainly three-year-olds."

Suzanne Held, who studies the cognitive abilities of farm animals at the University of Bristol�s Centre of Behavioural Biology, says that pigs are "really good at remembering where food is located, because in their natural environment food is patchily distributed and it pays to revisit profitable food patches."

Newborn piglets learn to run to their mothers� voices, and mother pigs sing to their young while nursing.

Pigs are actually very clean animals. If given sufficient space, pigs will be careful not to excrete near where they sleep or eat. Pigs don�t "sweat like pigs"; they are actually unable to sweat. Pigs like to bathe in water or mud to keep cool.

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