Surprising? Actually pigs are some of the the smartest, cleanest domestic animals known – more so than cats and dogs, according to some experts. For a famous experiment from the 1990′s, pigs were trained to move a cursor on a video screen with their snouts. When they were able to do this, they had to distinguish -by moving the cursor – between scribbles they knew and those they were seeing for the first time. They learned the task as quickly as chimpanzees.