Is my guinea pig happier alone?
Guinea Pigs tend to squeak more often when they want something, otherwise they can be fairly quiet animals. His running around could also be a sign of restlessness.
Guinea Pigs are very social animals, and tend to enjoy having friends around (provided that they are given an ample amount of space to live in). Having another Guinea Pig, especially if you cannot be with them as often, is an ideal way of keeping them happy and healthier. They’ll groom each other, and entertain one another while their human friend is away.
Be careful though when you introduce another Guinea Pig in, they are still shy with newcomers, and that can include another Guinea Pig. Put them in seperate cages and put them nearby each other for a while until they grow accustomed to one another and then put them together supervised to see how it goes. Hope that helps!