Gerbils are native to many parts of the world, but the type of gerbil most commonly kept as a pet is the Mongolian.
Gerbils come in a variety of colors, but usually have white fur on their belly. Their tails are covered with hair, unlike those of mice.
Gerbils usually live for three to four years. Most are nocturnal, but Mongolians are not. All gerbils are very frisky, and can easily escape from a cage that isn't closed securely. Their eyesight isn't very good, so they sometimes fall off of tables when they are running around loose, but their hearing and sense of smell are both very acute.
Gerbils must be treated gently, so children interacting with them should be supervised by an adult.