Why do Pigs Wallow and How do they Build One?

Pigs wallow primarily to regulate their body temperature and protect themselves from external parasites and sunburns.  Here's why and how they do it.
Cooling Off:

• Pigs don't have sweat glands, so they use wallowing as a way to cool down.
• The moisture on their skin evaporates, helping them lower their body temperature in hot weather.

Parasites:

• Mud or water in a wallow can help to dislodge and drown external parasites like ticks and mites that may be on the pig's skin.

​Sunscreen:

• For pigs, particularly fair skinned ones, covering themselves in mud during the warmer months provides them with natural sunscreen

As for how they build a wallow:
Digging:

• Pigs use their strong, snout-like noses to dig a shallow depression in the ground, creating a small pit.

Adding Water:

• They then often use their mouths to slurp up water from nearby sources, such as puddles, streams, or troughs, and spit or splash it onto the soil in the pit.
• In captivity they are known to drag their water dish over to a rooted out hole and dump the water in to make mud.

Mixing Mud:

• By stirring the water and soil together with their snouts and hooves, they create a muddy mixture in the depression.

Pigs are incredibly intelligent animals, and wallowing is a natural behaviour that serves important purposes in their lives.