Fis forFish tank
A fish tank is a glass container you keep pet fish in. You can also keep turtles, hermit crabs or even mice, lizards, frogs and snakes in a fishtank. Obviously, if you are keeping land animals in a fish tank you don't fill it with water, you put dirt in the bottom and grow plants. A fishtank with plants in it is often called a vivarium. You usually keep mice in a fishtank with sawdust at the bottom instead of dirt, so you can regularly change the sawdust to keep it clean.