Average Weight: 12.3-23.9 ounces (rats); 0.4-1.4 ounces (mice)
Lifespan: 2-3 years (rats); 1-2 years (mice)
Although most people would cringe at the thought of owning a rat, they are actually laid-back, intelligent animals and totally kid-friendly. Known as the "dogs of the rodent world," rats love to play and interact with humans.
Rats can be taught simple tricks such as retrieving objects or navigating their way through mazes. Give them cardboard toilet paper rolls or some string, and they will happily entertain themselves. Rats are also sociable creatures that thrive in pairs.
Mice, on the other hand, are a little trickier. They're easy to pick up and carry, but they're also extremely active and, like the hamster, prefer their independence.