Anger
When a pig is angry his fur will stand on end,he will display his large incisor teeth and will make a grumbling sound. They tend to pace with their back legs on the spot and sway their behind.

Happiness
When a pig is happy it's squeak will sound like a wavering chuckle and he will sometimes run, spin and kick it’s back legs into the air. Some people call this 'popcorning'.

Meeting other cavies
When cavies meet they may sniff their each other's bottom or nose. This is to smell their scent to tell if they are a friend.

Enemy confrontation
He will react the same as anger but will also make a loud chattering sound to inform the other that he is annoyed. If a fight arises, he will stand on his hind legs and lift his front leg ready to swipe his opponent. They will ram each other with their heads.

Fear
The timid cavy will twist his head away when in fear. When a strange sound has been heard he will lie still and not move at all until he is certain all is safe. They believe they go unseen if they stay still. In other cases they suddenly run about in a frantic fear.

Don't touch me!
He will make a rather grumpy sounding low toned chuckle and stay where he is. He may also throw his head back while being stroked to say that he wants to be left alone!

Dominance
In both sexes one of the most obvious forms of a dominance act is when they mount eachother. It is not necessarily a display of sexual interest, more of acertaining who is the boss of the pack. I find that males perform this act more often than females but it is still done.

Sudden pain
The cavy will either make a loud 'falling' squeak or will do the opposite and make a sharp 'climbing' tone squeak.

Demanding
An enthusiastically,high pitched "wee wee!" sounding squeak. This usually happens when they hear or smell food, but is definately a sound for when they want something. If guinea pigs are kept indoor it is not uncommon to hear them squeaking when they 'smell' a door is open; this means that that want to get into the garden!

Bird-like chirping
This is a rare sound to be heard and i only began hearing it lately since i got my sows. I had read about this but found the information to be contradicting. It is said that you're likely to find a young boar standing on his hind legs who is the one that performs the funny sounding act but whenever i have heard it it is one of my sows and they don't stand up to do it. The sound is a very shrill, and unmistakable bird like chirp; everyone who has been in the vacinity to hear it have thought it was a bird in the house! The sound will continue in the same tone chirup for several seconds. I am yet to come across a proven reason why they do this, but my belief is that it may have something to do with when a sow is in heat.

Dropping eating
This is a perfectly normal and necessary procedure for the cavy, called coprophagy. You may catch him taking his droppings directly from his bottom to eat. These droppings are softer than normal body waste and still contain vital vitamins that his body can not extract first time round. This action is similar to that of a cow chewing it's cud. He therefore needs to re-ingest them.