Pigs are one of many animals that wallow in the mud, using the roll in filthy water to keep cool in the absence of sweat glands. And that particular arrangement might be just how ancient pigs liked it ...

Checkers the pig is up for adoption, according to the Peninsula SPCA. The 17 lb. pot-bellied pig will grow up to 100 lbs. and requires outdoor yard space. Pot-bellied pigs are smart, perhaps even more ...

But he does love some mud. Using his shovel-shaped head, he makes quick work of a particularly sludgy part of a grassy knoll, creating his own mud wallow. He flops his big body down and rolls around ...

DEAR DR. FOX: Please settle an argument I am having with my brother, who insists that dogs are smarter than cats and that pigs are really stupid because they wallow in mud and get all dirty. — H.F., ...