Gerbils are about the same size as a small hamster. They weigh between 2 to 4 ounces and are about 4 1/2 inches long. The tail is as long as a gerbil’s body and is covered with fur. The hind legs are very muscular and they have large feet. Gerbils often stand on their haunches when not moving instead of crouching down. They often have a golden coat with white underbelly but gerbils can be a variety of different colors. A gerbil will usually live 3 to 3 1/2 years.