Rats
These rodents actually make good pets. They are people-friendly and much more sociable than pet mice. My family has had both kinds of rodents, so I'm speaking from experience! When I was a kid, we had a ground squirrel as a pet, but that's a long story (smile).
One negative about rodents as pets in general is that they don't live very long. It's hard to see them go when you've only had them around for a few years. They are also sadly susceptible to cancer.
Other rodents that can be pets are chinchillas, gerbils, hamsters, and guinea pigs.
Did you know that there is a super-sized rodent called the capybara? These are the largest rodents in the world, and they are from South America. Capybaras can be as big as four feet long! If you get a chance to see one in a zoo, they're actually pretty cute for the size.