Guinea pigs helped thwart a villain in last year's G-Force, but as family pets -- along with gerbils and hamsters -- they're cuddly, social, and pretty easy to care for. What to know before you bring one home:
Hamsters, gerbils, and guinea pigs, if they are siblings, may do well in pairs (same-sex ones, unless you don't mind babies!). But don't mix species, and be careful to house Syrian hamsters (a commonly sold variety) alone, since they're very territorial. Consider adopting from a local shelter -- you'll pay less than at a pet store.
Make your new friends comfy
Provide at least a 20-gallon aquarium for hamsters and gerbils, and a two by three-foot cage for a guinea pig (two by four if you have a pair). You'll also need a food dish, a water bottle, an exercise wheel, and bedding for sleeping and burrowing. Wood pulp makes the best bedding -- avoid using sawdust and cat litter, which contain too many fine particles.
Serve the right bites
Hamsters and gerbils like a nut-and-seed mixture (ask a vet for recommendations), while guinea pigs prefer pellet food. "Skip table scraps, because some fruits have too much sugar and processed foods aren't good for them," says Adam Goldfarb, spokesperson for the Humane Society of the United States in Washington, DC.
Follow doctor's orders
You'll need a vet who specializes in exotic animals -- she may also be able to neuter your pet, if you want.
Keep things tidy
A clean cage is key to good health, so empty and wipe it down each week.
Handle with care
Until your child is used to your new pint-size pal, be sure to hold it while he practices learning how to pet it very gently.