Guinea Pigs Are Moreish, You Can't Have Just One
Like candy, guinea pigs tend to be moreish little creatures, it's hard to have just one, in fact, you should never keep just one guinea pig alone. Why? Because guinea pigs are community creatures. A guinea pig needs the companionship of its own kind, and that means you should always keep guinea pigs in pairs.
Some people used to think that it was a good idea to keep guinea pigs and rabbits together. In fact, I thought the same when I got my first guinea pig. I quickly learned that this was a falsehood as I watched Wicket, my terrible wee bunny, chase the guinea pig around 'her' hutch, trying to bite him. Rabbits are very territorial creatures, and it's hard enough to introduce a new rabbit to a rabbit, let alone a silly creature like a guinea pig. A rabbit will be offended if you invade its space with a filthly little rodent, and rightly so.
Guinea pigs deserve and need their own quarters, and despite what you might think from the way they just sit around huddling in pet stores, they need fairly large enclosures in order to be really happy and healthy. Guinea pigs do love to run about and play, so make sure that your hutch is at least three feet by two feet wide. If your hutch is smaller, consider upgrading very soon. There are cheap and inexpensive ways to make guinea pig hutches. Coroplast cages are all the rage at the moment, and they are quite cheap to make and allow for very large running spaces. Check out Guinea Pig Cages dot Com for some very good DIY guinea pig cage ideas.
Once you have your pair (or more, you can always have more, assuming they are all the same sex, mixing males and females will mean that you end up with more guinea pigs than you can humanly handle. If you want to breed your guinea pigs, make sure that you have separate quarters for males and females when they are not breeding and that you also have separate quarters for mums and babies. Breeding is no light matter and not something recommended unless you have the space, time and money to do so.
Remember too, guinea pigs love toys! Hidey holes, tunnels, snuggle sacks, they are all very popular with guinea pigs.
Enjoy your fun, furry little friends, and remember, keep two or more!