Kiss Me ! The domestic pig is born as an adorable pink piglet that weighs just 3.3 pounds (1.5 kilograms). They don’t stay that small for long though; they double in size by the end of their first week of life. Pigs are the forth most intelligent member of the animal kingdom; at just two weeks old, baby piglets already know their names and will respond when called. Pigs are very warm and social creatures that form close bonds with each other, and other animals.