Companion for aggressive pig

Question
My Wife and I have a 17 month old pig who is an indoor pet.We have occasional problems with his agression, specificly biting. Carls agrression is mostly towards guests espicially when they are in our home or his territory, but sometimes he is aggressive towards myself also. we have read that pigs often have fewer behavioural problems if they live with another pig. For this reason, we are considering adopting a companion for our current pig. Is this something you would recomend?
We have read Pricilla Valentine's book about pig behavior and are following its adivce to the letter. Would you recomend any other sources of quality pig advice to correct aggressive tendancies?

Answer
Pigs can be territorial, and they reach emotional adulthood at age 2. Pigs see the world as a ladder, with each person, pet or pig having his or her own rung. Young piglets don't mind being at the bottom of the ladder, but adult pigs want to move up.

Pigs often target visitors first, because the pig sees the visitors as "outsiders" in his territory. So he's going to show them who's in charge! From here, the problem can escalate, starting with the pets and people that piggy thinks are the easiest targets.

Getting another pig can improve a lot of behavior problems, but it isn't always the best solution to territorial aggression. If the goal is to keep piggy as a primarily indoor pig, and be able to have piggy and visitors both in the same room at the same time without aggression, then the solution is to teach piggy to respect visitors.

Start slowly with a single brave visitor. Put piggy on harness and lead before the visitor arrives. Hold onto the lead and invite the visitor in. Have piggy meet the visitor. Make piggy do a few tricks for treats, like Twirl or Down. Then have the visitor make piggy do a trick or two for treats. Now quickly end the visit, before piggy has a chance to misbehave.

Repeat this with two visitors, then three. Then gradually extend the length of the visit. Keep piggy on harness and lead at all times, and, after piggy is finished performing tricks, hold onto the lead.

Watch piggy carefully. If you see signs of stress, or piggy acts like he's preparing to charge, take piggy back to his safe space at once.

If you can't kick your visitors out right away, after piggy has done the meet and greet and performed his tricks for the visitors, take piggy back to his safe space or to a secure outdoor pen until the visit is over.

Often moving piggy to mostly outdoor life with visits indoors dramatically reduces aggression for two big reasons. First, outdoor time gives piggy a chance to do natural piggy things like snurdle and root in the dirt, releasing pent up energy and frustration. Second, piggy no longer views inside the house as "his" territory. "His" territory is the outdoor shelter and pen, indoors is "people" territory.

There's an email group called Pig Info and Chat (it might be PigInfoandChat) in Yahoo groups. Lots of experienced pig people there who are happy to answer questions and talk about their pigs. This group was originally established by Priscilla Valentine before she passed away.