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Quick, what is a Cavia porcellus?

If you know it is a guinea pig or cavy (another word for guinea pig), then you probably already have one of these sweet little creatures. Today we are going to look at a few science activities you can do to learn more about guinea pigs.

Guinea pigs are small rodents originally from the grasslands along the west coast of South America. Well, at least scientists originally thought they were rodents. Some studies of DNA sequences published in the journal Nature during the 1990’s seem to indicate that cavies aren’t rodents. The debate lingers on. If you are interested in genetics, this might be a science topic for you to tackle in the future. (If you need to brush up on what a rodent is, check links in the “Science with Your Pet Mice” post.)

There are some other South American animals that are relatives of domesticated guinea pigs. One is a small brown animal named Cavia aperea. Others are the so-called yellow-toothed cavy, Galea musteloides, and the Muenster yellow-toothed cavy, Galea monasteriensis, which wasn’t discovered until the late 1990’s. More distant relatives are the Patagonian cavy and even the capybara. There are a lot of interesting rodents in South America. See if you can find pictures of them.

Guinea Pig Anatomy
Learning about the parts of your guinea pig can help you understand how your guinea pig functions, and help you determine if your guinea pig is healthy. Here is a website that discusses details of guinea pig anatomy (probably for older children).

Back from when I was a student, I still remember another graduate student complaining that during his thesis defense exam one of the professors asked him "What other mammal besides humans lack the ability to make its own vitamin C?" The student didn’t know the answer, but I did. One of the first things you need to know to keep guinea pigs as pets is that they need vitamin C added to their diet because they can’t make it themselves. You need to use foods that are specially made for guinea pigs, and add fresh vegetables to their diet that are high in vitamin C. Some examples are kale, parsley, and limes.

Guinea pig breeders also recommend feeding guinea pigs hay. Hay is dried grass. As well as being an aid for their digestion, it also helps keep their teeth in good shape. It makes sense they would like grass, since they are originally from grasslands.


Once you’ve covered the nutritional basics, you might want to give the guinea pigs some food choice tests to see if they have any preferences. One of our guinea pigs seems to love grapes, where the other one could care less. The grape-loving guinea pig runs away from tomatoes, though. See previous pet science posts for ideas about setting up a choice test to determine what foods your guinea pig loves best. Just remember to always supply lots of pellets and hay so they never get hungry.

Growing Wheat Grass
Gardening for your pet is always fun. Here are some instructions for growing a mini-garden indoors, which your guinea pig is sure to enjoy. (You should check this one just for the pictures). Cats like grass too. If you choose to use soil, make absolutely sure it is organic. Some soils may contain pesticides, which could harm your piggie.

If you find that you like doing this, grow some sprouts or wheatgrass for yourself to eat, too.

In nature guinea pigs live in burrows, so they like to have a house to retreat to. A fun project is to design and build a house and see how the pigs like it. You can use cardboard boxes and tubes, or if you have access to woodworking equipment, try wood. Just be sure to use materials that are non-toxic.

Our piggies let us know they thought one of the cardboard houses we provided was too small. They played “flip that house” with it.

Guinea Pig Sounds

I talked about how cats use sounds to communicate last week. It turns out that guinea pigs make an interesting assortment of sounds as well. If you have a guinea pig, listen and record the sounds it makes. Some of the sounds might be described as coos, squeaks, and teeth chatters. Oh yes, and the loud “wheek, wheek, wheek” whenever the refrigerator door opens.

If you don’t have guinea pigs, hear some at Jackie’s Guinea Pigs.

Because guinea pigs tend to be timid and run and hide when startled, some people have dismissed their intelligence and disregarded the notion that you might be able to train them. It turns out that guinea pigs are quite intelligent and engaging. With gentleness and patience, you can teach a guinea pig a few tricks.

(Video has music and a pop-up ad.)

Although getting your guinea pigs to do tricks like that looks like a lot of fun, it also takes time and patience. You might want to start out with behavioral enrichment. What’s that? It is simply providing an interesting and safe environment for your guineas so they don’t get bored. Most guinea pig guides now suggest that you get them out of their cage for at least an hour per day. Provide a safe place for them to exercise and explore. Provide toys such as mirrors, balls and bells. A small box full of shredded paper with a hole in one side will provide them something to explore. Just be sure your guinea pigs seem relaxed and interested. If they seem restless or scared, try to provide something for them to hide under until they feel safe, or return them to their cage and try again later.

By the way, be alert to the fact that guinea pigs often won’t urinate or defecate while away from their box. If your guinea pig seems uncomfortable and has been outside for a while, put him back inside his cage for a little while. Yes, some guinea pigs can be housebroken.


And speaking of needing to go, I seem to have wandered on here more than I intended. If you have any further questions, feel free to leave a comment.

Books with more information (linked titles and images go to Amazon):

For an introduction to guinea pigs for younger children, you might want to try:

I Love Guinea Pigs: Read and Wonder by Dick King-Smith and Anita Jeram (Illustrator) Dick King-Smith has some wonderful fiction books told from the point-of-view of animals. In this case, he has written a nonfiction book that is an introduction to owning and caring for guinea pigs. Note: This book does address the issue of death of a pet.

The Proper Care of Guinea Pigs by Peter Gurney
Peter Gurney is a beloved advocate of guinea pigs, who was well known in the community of pet owners.

The Guinea Pig Handbook (Barron's Pet Handbooks) by SharonVanderlip , D.V.M.

Guinea Pigs (Animal Planet® Pet Care Library)by Julie Mancini

Training Your Guinea Pig (Training Your Pet Series) by Gerry Bucsis and Barbara Somerville contains information for taking care of guinea pigs as well as suggestions for activities.

Gordon's Guide to Caring for Your Guinea Pigs (Pets' Guides) by Isabel Thomas is illustrated both with color photographs and with humorous illustrations of Gordon the guinea pig, who narrates the book. It covers the basics of guinea pig care clearly and concisely. Everyone who is thinking of adopting a guinea pig would do well to read this book first.

(Full review at Wrapped in Foil blog)

In the most recent issue of Muse magazine (September 2008) is a moving story about the scientist/artist Anne Adams. She was a Canadian scientist who gave up her career to become an artist. In a sad twist of fate, her newborn interest and incredible ability in art was probably due, at least in part, to a rare brain disorder.

I was able to find a link to a project she did with her husband, called “An ABC Book of Invertebrates.” Anne did the illustrations and her husband, Robert Adams, composed the text. The illustrations are like looking through a kaleidoscope, with colorful, repeating patterns. The earthworm image is amazing (click on E ).  Too bad some of the scans are not completely clear. I’m sure children that are interested in unusual creepy crawlies will still enjoy it.

To read more about Anne Adams story and the brain disease she suffered from, check this article about how one of her paintings entitled “Bolero” came to be.

What would you do if you found one of these bright red creatures in your yard?

pipevine caterpillarpipevine caterpillar

You should cheer because they are the caterpillars of the beautiful pipevine swallowtail butterfly (Battus philenor). We found these at the Boyce Thompson Arboretum in Arizona.

The bright red caterpillars will turn into one of these butterflies.

pipevine butterfly

Check out the gorgeous metallic blue on the lower parts.

I should admit right away that it is extremely difficult to get a good photograph of a pipevine swallowtail butterfly. The butterflies have a behavior known as “flutter feeding” which mean their wings are in almost constant motion. This one was on the floor in a public place, so I suspect it may have been stepped on. Too bad.

The caterpillars of the pipevine swallowtail feed on plants called pipevines (Aristolochia species), hence the name. The plant is a small, drab vine and is hard to spot. I am grateful to my friend who pointed out this one. Edit: My friend says this plant is Aristolochia watsonii.

pipevine plant

The plants contain a nasty chemical called aristolochoic acid that deters most animals from feeding on them. The ability to feed on pipevine plants is a unique feature of these caterpillars.

The caterpillars change size and color as they grow. You may also see pipevine caterpillars that look like the ones above, but are black instead of red.  The larger, older caterpillars are often found resting on plants besides their hosts (the ones they feed on). The caterpillar above is not on a pipevine.

On the same day we also saw this little butterfly.

bordered patch butterflybordered patch butterfly

This is the adult of the bordered patch (Chlosyne lacinia). In some books it might be called a lacinia checkerspot. This little guy is really quite battered.

The bordered patch species is also quite variable in color, like the caterpillars of the pipevine. The North American Butterfly Association has a page of photographs of members of this species. You will see this dark color version towards the bottom. How did anyone ever figure out they were all the same species?

I was not surprised to learn the bordered patch caterpillars feed on sunflowers (as well as ragweed). Here is the garden that was only a few feet away from where I found the butterfly. If you want to raise butterflies, just plant a few of these.

sunflower garden