Pigs are super clean animals!
But wait! Pigs love rooting into the mud. How can they do that but be a clean animal? Most people don't realize that pigs use mud as a sunscreen and a way to cool down. Pigs can only sweat through their nose, so to cool their body down they must get creative. And they are intelligent enough to figure out that the deeper they deep, the cooler the ground gets.
But, in nearly every other way, pigs love being clean. Pigs will not use the bathroom where they sleep or eat if at all possible. Many wild pigs will actually create a public restroom where they can go to keep their bathroom activities private. This helps keep their living space clean and protects them from predators finding their herd.
Unfortunately, most people are thinking of pigs on farms like those run by Smithfield Foods where pigs are forced to live in unnatural conditions cramped together in ways that make being clean impossible. This results in pigs being forced to live in their own waste and is one of many reasons that these poor animals are so miserable.