A guinea pig is a tube with a brain. Stuff goes into this tube at one end and comes out of the other. The purpose of the brain is to cause the tube to find more stuff to eat. Just underneath the brain, near the feet, is a squeaking muscle shaped like a kidney bean. If the brain thinks, even just for a second, that there is the remotest possibility of food, anywhere, within a fifty mile radius, then it sends a signal to the squeaking muscle, which then squeaks. Squeaks can also be elicited by tissues, your homework, feathers, and the rustling of plastic bags, all of which are incredibly delicious to the guinea pig.
I'm a guinea pig, big and chubby...what can I eat? Hay and pellets, fruits & veggies, Vitamin C!