I remember reading in Reader's Digest back in the 90s that some people who had the small furry pigs as pets found out they could open the refrigerator even if they taped it shut or put a latch on it. If they put the latch up high, the pig would push a chair over and climb up there! Can't find that article, but here's some supporting evidence of their intelligence:
Pigs are absurdly smart, easily smarter than most dogs. Our pigs growing up were dangerously clever, and would devise elaborate methods to escape and bully us kids.
https://www.superpages.com/em/basics-pot-bellied-pig-care-fe...
https://www.msn.com/en-gb/travel/other/cunning-pig-in-china-...