Here is a pic I took at the sanctuary of our youngest pig, Owen (5 months) with our oldest pig Bruce (9 years). Owen has taken to grooming all the older pigs. He spent a good five minutes grooming Bruce's face. It was pretty damn precious.
Owen was found in the middle of the road by a kind stranger. He was only a day old. He would have been raised on a "free-range" farm and sent to slaughter at the age of six months.
Bruce was one of the worst cruelty cases we have seen. He had been left to die of starvation. He had been on the farm for seven years before we stepped in and literally had to order animal control to save him. When he arrived at the sanctuary, he was literally a skeleton with a hide draped over him. It took several months of TLC, but he survived. Because of his social isolation, he never knew how to grunt properly (pigs are VERY vocal). It is considered an honor when he grunts in greeting.
It is truly an honor to work with such gentle, silent teachers.
Except when they're loud and ornery. :)