Rats make excellent pets because they are easy to care for (although they need attention, as in playing, especially if, for some reason, you only have one) are very smart, are unobtrusive, are very cute, and do not normally cost as much as dogs to keep and care for well. They also can have a considerably longer lifespan than mice, which is better for the owner emotion-wise. Plus, young (almost baby) rats look like puppies, which is good if you like dogs.