Since pigs spend most of their time out in the hot sun, they must take measures to prevent their skin from sunburn and keep their body temperature within normal limits. Wallowing in mud creates a protective coating on the pig's skin and assists in evaporative cooling—a pig's version of sweating.

Why do pigs love rolling in mud?

Pigs lack functional sweat glands and are almost incapable of panting. To thermoregulate, they rely on wallowing in water or mud to cool the body.

Are pigs happy in mud?

Mud baths certainly keep pigs cool, a newly published research review finds, but wallowing may also be a sign of well-being in swine.