One of the guinea pig's traits that really sets it apart from other small pets is its way of communicating with you and with other animals. Cavies have an array of physical and verbal communication methods that make it easier for you, as the owner, to get inside their head, see what their thinking, and provide them with what they need.

Because their methods of verbal communication are the most unique, we'll start by discussing those.

Many first-time guinea pig owners have often heard rumbling or clacking sounds coming from their tiny creature's cage but never really suspected that those noises were coming from their pet, but they are. In fact, a group of rowdy guinea pigs can get real noisy, real fast.

Guinea pigs have a set of around 7 different sounds (some have subtle variations as well) that were originally used to communicate with their herd in the wild. Each sound has a distinct meaning and is often reinforced with appropriate body language.

Let's look at some of those meanings.
1. Low rattling sound - This deep, constant sound signals to the guinea pigs of the opposite sex that he or she is in the mood. Also, if you have two or more female guinea pigs, you may hear this noise when the dominant cavy greets the others.
2. Rumbling sound - This sound is a signal that your guinea pig doesn't like something. If you are petting him, then that means it doesn't feel comfortable with how you are touching him. If he is alone in his cage, it might mean that there's a loud sound he doesn't like.
3. Squeals/Whistles - Normally, this sound is never used with other guinea pigs. The animal has developed it for one purpose: to ask humans for food.
4. Clacking teeth - If you have several guinea pigs in a cage together, you will definitely want to listen for this sound which is a warning and a signal of aggression.
5. Shreiks - Guinea pigs make this sound when they feel afraid, lonely, or in pain. If your pet makes it, then you need to figure out why and resolve the situation so your guinea pig can return to being happy.
6. Grunts/Squeaks/Chirps - you will, hopefully, become all too familiar with these noises since the guinea pig uses them to let you know he's happy and comfortable. It's also the basic sound used between guinea pigs as they communicate with one another.
7. Purrs - These soft sounds may remind you of a cat as it rubs on your leg, and both the cat's and the guinea pig's sound means pretty much the same thing: they like whatever you are doing a lot!

Many pet owners want to know the secret of getting their guinea pigs to purr, but there really is no secret that they can find in a book. Each guinea pig is different, and each likes to be held and petted in different ways. If you want to make your guinea pig happy, the best thing to do is to experiment and to listen to what he tells you. He'll let you know what he likes and what he doesn't like; you just have to pay attention.

Just as their verbal messages can help you interpret their feelings, so can guinea pigs' body language.

One of the most common things you may see your guinea pig do is to jump straight up into the area or to make several successive jumps in a row. This behavior is referred to as “popcorning" since the guinea pig resembles the popcorn kernals popping around while they are being cooked. This tells you that they are in a great mood and that they are very happy.

Guinea pigs also like to stretch their bodies. This also is a sign of being content. However, if they are only stretching their head that means they are very alert and are paying attention to what is going on around them very carefully.

When you hear that teeth clacking or rumbling sound, it's a good bet that you will either see your guinea pigs showing their teeth or standing up on their stiff back legs. Both of these are signs of aggression and could signal an impending fight.

Keeping a watchful eye and ear on your guinea pigs can help you provide them with everything they need to be truly happy and safe.