I've had my guinea pig shane for a year or so now. He was given to me by my uncle, who received him from a lady that was trying to return him to a petshop. I know guinea pigs are herd animals, and rather social (Or so I have read) and are better kept in pairs, or trios... but I was wondering... how necessary is this? and if it is necessary, how can I introduce shane to a friend? I'm very unsure of how to go about this. He's not exactly young so will he take to a random piggy? Also, I can't have baby guinea pigs running around... can I get a female piggy that is spay? I'm fairly certain my cage is big enough for two piggies, and shane is very friendly with people and other animals (cats/dogs) so will that help determine if he is good with other piggies?