: Cavius Porcellus, hence its nickname 'cavy
The guinea pig is a small rodent native to the Andes mountains of South America. Among the locals there, it is a popular dish.
Guinea pigs got their names from the loud, high-pitched squealing they make when they are hungry, or when they are scared, or when they want to be held, or for no damn reason at all. It sounds like this: 'Week week week Weeeeek week WEEEEEEEEEEK!!! WEEEEEEEEEEEEEEEEK!!!! Week week week weeeeek' and it just goes on like that until you give it a carrot or some other leftover vegetable to shut it up. This is why guinea pigs are usually fat. They also make a satisfying purr sound when you pet them.
Guinea pigs come in a few varieties, but the most common are smooth-coated and abyssinian. Smooth coated guinea pigs look like overinflated rats, and have a shiny coat of short hair. Abyssinian guinea pigs are the closest terrestrian relative to the tribble. They are covered with thick long hair that is intensely whorled. I had a solid black one once named Pudge, and it was difficult to tell which end was the front.
Although the squeaking can get annoying, guinea pigs actually make pretty cool pets. They are social creatures, and will learn to enjoy being petted and held, unlike gerbils or hamsters, who seem to only learn how to restrain their terror. The fact that they are pretty cute helps as well. Care for a guinea pig means keeping it in a cage with newspaper or wood chip bedding that should be regularly changed. Food is store-bought GP chow, augmented with leftover greens from the salad you should be eating every night or two.
My sister and I had a male and female guinea pig when we were younger. When the female is in heat, it is a terrible thing to behold. When we kept them in separate cages, Pudge got as close to Amy as he could, and squeaked as loud as we'd ever heard until we gave in and put him in the same cage as her. Then it was Amy's turn to start squeaking at top volume as Pudge had his way with her. His purring was a nice touch as well. Pudge was a black abyssinian, and Amy was a smooth-coated agouti (the natural color of wild cavies; it's a kind of silvery hair). The babies were all sorts of calico colors, but all were abyssinian. They were very cute balls of fluff, and unlike hamsters, Amy never ate one (that we saw).
Guinea pigs live about 4 years, with good care and love.