Pigs often thought to be being lazy and dirty animals, but they are, in fact, very intelligent. Pigs have the ability to learn quickly and adapt to a variety of environmental conditions. Pigs do not have sweat glands and are therefore unable to sweat and control their body temperature during warm weather. To cool themselves down, pigs often roll in mud and dirt. Creating a layer of mud on their skin protects them from the sun as well as insect bites.