Communication and body language
Guinea pigs communicate with both sound and body language. When walking around together in the cage, or on the floor, they will often times squeak and grunt as they move about, which is a sign of general contentment. If a guinea pig, particularly a baby, gets lonely, it will squeal loudly, asking for reassurance. Guinea pigs that are housed alone will often make this sound, requesting human contact from their owners. The guinea pig will also squeal loudly when it suspects that food is on the way. This begging for food is reserved exclusively for humans. Guinea pigs also squeal when they feel that they are in danger, which acts as a warning to others in the herd. This squeal is typically more panicked than the squeals for attention or food, and several squeals may be emitted in rapid succession.
When you pet a guinea pig, you will often times begin to hear it squeak or grunt, or even coo softly. These are sounds of contentment and pleasure, are are one of the main reasons why guinea pigs are so adorable as pets. If, however, you touch an area that they don't like (such as the sides of the tummy in a pregnant female, or the very bottom of any cavy), you might hear a rumbling sound, which serves as a warning. This rumbling is also made by guinea pigs when they hear sounds that they do not like (such as your upstairs neighbors banging on the floor, or a sharp snare drum on the radio), or when they want to warn others when something "isn't quite right".
When two females meet, the lower rank one might address the other with a rumbling rattle that sounds like the male arousal sound. The lower rank female will lower her head, thus asking for a truce from the more dominant sow. Sometimes, the dominant sow may feel threatened by this act, and will respond with angry chattering. In both male and female guinea pigs, this teeth chattering is the precursor to a fight, and nasty bites can follow if no one backs down.
The low, constant, rumbling rattle that a male makes when aroused is definitely a sexual behavior, but some males and females will often engage in mounting activities as an expression of dominance. Females may mount females of a lower rank, or even the male. Of course, when a sow is in heat, she will make this same purring to signal the male that she is ready for mating.
When your guinea pigs are in high spirits, you may see them leap straight up into the air while curving their backs, or run across the floor and make several shorter leaps in rapid succession. This jumping, commonly referred to as "popcorn jumping", or just "popcorning", is the sign of a healthy and happy guinea pig, and is one of the real gems in guinea pig behavior.
The following tables are excerpts from Behrend's book, with a few additions, and describe many of the sounds and some of the body language that guinea pigs use.
Body Language
Body Language Meaning
Rising up with legs stiffened------Threatening
Shows teeth with mouth open-----Used by females to deter advances from a male, and by both sexes as a threatening posture
Stretches-------------Comfort, relaxation
"Popcorns-------------High spirits
Stretches head forward------------Watchfulness
Verbal Language
Sound Meaning Grunts, gurgles, squeaks----Contentment, comfort, contact with other guinea pigs through sound
* Squeals, shrieks-----Warning, young's cry of loneliness, pain, fear
* Squeals, "wheeting"---Begging for food (reserved for humans)
Cooing-----Reassurance, usually uttered to young Rumbles Warning, dislike of an action or sound Hisses, teeth clacking Aggression, threatening opponent, warning
Rattling, rumbling------Arousal sounds (male and female), lower rank female greeting a higher rank female
Senses and Intelligence
It has often times been said by persons not familiar with guinea pigs that they are not very bright, or are boring animals. While it is true that they are not rocket scientists, guinea pigs are in fact quite alert, very trainable and respond well to sounds and smells. The fact that they don't seem to behave intelligently as animals such as rats stems mostly from human expectations.
Guinea pigs are herbivores. The intelligence needed by hunting animals and scavengers is not a part of their programming: after all, it doesn't take tremendous hunting skills to be able to sneak up on a blade of grass. What naturally engages a guinea pig's intelligence in the wild isn't normally called upon in their life as a pet. In nature, the guinea pig survives through the use of effective herd communication, establishment of well known trails and rapid reproduction. They have a varied vocabulary, a cautious curiosity and the ability to learn the many paths between their lairs and their feeding grounds. Of all these defense mechanisms, the practice of establishing well-traveled and well-known routes to and from their lair is arguably the most important. The guinea pig learns these trails so well that they can dart almost effortlessly through them, typically faster than their predators can follow. By ducking through thick brushes and around sharp turns quickly, they can evade even the most determined pursuers. When danger is suspected, the guinea pig will also warn the other members of the herd so that they can protect themselves. Typically, this leads to the "scatter response", whose intention is to split the herd up so that one predator can not make a meal of the entire family. When guinea pigs feed, one animal will always assume the duty of a "lookout".
Learning and training
It seems that guinea pigs learn mostly through repetition and association of cause-and-effect (which can also be thought of as classical conditioning, in psychological terminology). In particular, as with many animals, their zeal for learning is greatest when food is involved. All of this makes the guinea pig very trainable; they can learn to use a litter pan when outside the cage, and even come when their name is called. It takes a great deal of patience, and several sessions with your pet, but the potential is there.
To potty-train them, it's best to start by taking them out of the cage for only a few minutes at a time and letting them run around on the ground. Put them back in there cage, and wait for them to pee. After they do this, bring them back out. If you see your guinea pig get anxious on the floor, back into corners or perform other pre-toilet activities, put them back in their cage, and then reward them with a treat after they pee before letting them back out again. Eventually, they will get the idea that the cage is for peeing and the carpet is for playing.
Most guinea pigs learn quickly that the cage is a safe place, and as a general rule, they will litter in familiar territory. This does make potty training easier, provided you never let them establish a litter spot somewhere on the carpet in the corner of your room. If you opt to let them roam the house, or part of it, at will, it is inevitable that you will have a few accidents. Some well-placed litter pans can reduce, if not eliminate all of these.
Guinea pig poops, however, are harder to control, as they not only drop them at seemingly random times, but they also eat special, moist poops that are stored in a small sack inside their anus. These poops are essential to their health, but can be frustrating to owners, as they have no qualms about stopping whatever they are doing, wherever they happen to be, to reach down and eat a poop. And in doing so, they may eat half, and drop the rest where they are standing, which might very well be in the middle of your carpet. Senses
Hearing.-- Guinea pigs hear extremely well, which makes sense given their extensive "vocabulary". They can hear sounds up to 30 kHz in frequency, well beyond the human limit of 20 kHz. As pets, they can differentiate between the footsteps of their owners, and react differently to a particular person's approach. Many animals will become conditioned to sounds related to feeding, such as the opening of the refrigerator door or the rustling of their feed. They also respond very well to certain types of music, which can have a very relaxing effect on them. Smell. Though they don't smell as well as dogs or cats, their sense of smell is still considerably better than humans. Other guinea pigs are recognized by scent, as are their human owners.
Sight.
Like all herbivores, guinea pigs have eyes mounted on the sides of their head, giving them a tremendous angle of vision. This is necessary for survival, as it allows them to spot predators from nearly any direction. Their vision is attuned mostly to movement, and they do not "resolve" objects at a distance. Note that side-mounted eyes provide almost no depth-perception, so guinea pigs have trouble gauging distances and heights, which can lead to nasty falls if you are not careful. They do, however, see in color, and experiments have shown that they distinguish color very well, particularly red, yellow and blue.
