In their native high mountains and grasslands of South America, guinea pigs make their nests in tall grass and the abandoned burrows of other animals. In captivity, it's up to you to make sure that your guinea pig has a safe and comfortable home.
One guinea pig requires around 2 square feet of cage space but would prefer more. Guinea pigs are social creatures and like the company of others, but be careful not to crowd your pet. Add an additional square foot of space for every guinea pig that shares the cage space with your first one.
Most breeders argue against wire-bottom cages for fear that a guinea pig's small feet and ankles can easily get caught in the mesh. If you must choose a wire-bottom cage, be sure that at least part of the enclosure has a solid floor. An old baking sheet can be placed inside a cage to serve as a substitute for hard flooring.
Solid-Bottom Cages Recommended
Solid-bottom cages are better for guinea pigs' feet but they also trap moisture from urine and defecation. The bedding you choose can make all the difference for your guinea pig: ideally, it should absorb the urine and its ammonia odor and serve as a base for your guinea pig's nesting needs.
Several commercially available beddings like Care-Fresh are very good at controlling cage smells. Untreated wood shavings – pine and aspen shavings, but never cedar shavings – can be used as bedding, as can timothy hay. Straw and ground corn-cob bedding are less desirable because they mold easily and may harbor bacteria. Don't use cat litter in your guinea pig's home.
Lay down a layer of newspaper below the bedding and remember to use only the black and white pages of the newspaper. Glossy color pages may be toxic to your pet if sampled.
If your cage or hutch has a hinged top you can access the nesting space without worrying about escapees. Convenience is the key because your guinea pig's enclosure must be cleaned frequently: You should remove and change all bedding at least twice a week. Always move your guinea pigs out of the cage before you begin to clean. Keep your guinea pigs in a separate box with ventilation holes while you're cleaning – the box can double as a carrying container for vet trips.
Once you've decided on an enclosure and appropriate bedding, it's time to choose the cage extras. Remember that your guinea pig is a rodent equipped with long incisor teeth for gnawing and biting. Anything you place on the cage floor can – and will – be tasted.
Every cage needs an exterior water bottle and a heavy ceramic feed bowl (to discourage dumping). Your guinea pig will want a separate place to sleep and hide, like a cardboard box with a hole cut in it or a wooden birdhouse turned on its side. Be creative – four-inch diameter PVC piping makes a guinea pig tunnel; bricks and rocks can be great climbing toys. For a treat, give your guinea pig a branch from a fruit or nut tree to chew. But try not to clutter the floor with too much stuff; your guinea pig needs space for napping, too.
Your fully-furnished cage should be placed in a warm, dry room in your house. Guinea pigs are naturally timid creatures and need a quiet space where they can relax. The room should have good circulation, but be wary of drafts. Ideally, the room should be kept below 80 degrees Fahrenheit; guinea pigs have little tolerance for extreme temperatures. Do not place the cage directly next to a radiator or heat source and avoid full sunlight.