As we noted last time, rats can make good pets. If you’re thinking of getting a couple (just one is not a good idea), there are a few things you should know.

Try for adoption first. You’ll be giving the rat a good home, doing the former owner a favor, and making sure you get an animal that’s been cared for and accustomed to humans. Look for a rodent rescue group, like littlemischiefrescue.org. (“Mischief” is the word for a group of rats. The less colorful alternative is “pack”.) Yes, there are rescue groups for just about any kind of animal that’s kept as a pet.

If you can’t find one to adopt, buy from a breeder — NOT a pet store. “The sad truth,” say rat owners George and Debbie of Seattle, “is that most rats seen in pet stores are there to be sold as snake food, not pets.” They are at high risk for disease, developmental problems, and bad behavior.

You’ll need the biggest cage you can afford. George and Debbie recommend Martin’s “because they have multi-level designs, are easy to clean, and have ideal bar spacing to prevent foot injuries.” An aquarium may be tempting, but they’re not built to let air circulate, and toxic fumes can build up quickly.

Likewise, bedding and litter should be dust-free products, preferably made of recycled paper. Pine and cedar can give rats respiratory problems.

Food for rats should be 80% lab blocks, which you can get at pet stores. The other 20% can be treats and people food — as long as it’s healthy. There are a few exceptions: Chocolate, raw potatoes, and nuts are toxic to rats. Peanut butter can cause choking.

Then there’s the fun stuff, like a good quality running wheel of adequate size. George and Debbie recommend Wodent Wheels. Other toys can be bird ladders, cardboard tubes, or anything the rats seem to enjoy.

Remember, what they’ll enjoy most is playing with you.