Although not as intelligent as rabbits I still find that the more you give the pigs to do the more they want and enjoy. Sometimes I make them a huge playground area on the grass with tunnels, walls etc and they love it and pop corn around and busy themselves going in and out of things.
I would like to have a large slabbed run attached to their housing so the they could be out safely all day unsupervised. No space at the moment though.
Rabs