I have two gorgeous sows (1 yr 4 months) who have lived with each other for over a year.
They mostly tolerate each other's presence, but often bicker over personal space, bedrooms etc. Occasionally their arguments are worse and involve hair pulling and angry pouncing.
I've separated them in the past, but the daft buggers just pine for each other - even when they can communicate through the bars. Pathetic crying, heavy sighs, and attempts to climb into each other's part of the enclosure!
I'm very keen to add more piggies to my little herd, and I do have room to have separate living quarters for different personalities.
Might a neutered boar help with cage dynamics? Or perhaps more sows and separate according to who gets on with whom?