Physical Traits
Both gerbils and hamsters can grow up to 5 inches long. They are covered in fur, which can be white, brown, black, red, gold, orange or gray. Gerbils tend to have white stomachs and a thin tail that is the same length as the rest of their body, while hamsters have stubby (or nonexistent) tails. Both animals have poor eyesight, but good senses of smell and hearing. The two back legs of a gerbil are longer than the two front legs. All four of the hamster's legs are short.
Diet
There is not much difference in the types of food you should offer to a hamster or a gerbil. A diet consisting of grains, seeds and proteins is effective. Gerbils also enjoy alfalfa and timothy hay. Provide store-bought food as well. Supply treats, such as round oat cereal, fruits and vegetables, in moderation. Apples, bananas, carrots, lettuce and broccoli are good choices. Remove food that is perishable after 24 hours. Supply clean water daily. Never give your hamster or gerbil chocolate, candy or sticky food.
Behavior
Gerbils are social animals who are active during the day. Multiple gerbils can usually be kept in one habitat without a problem, though they may need to be introduced to one another by placing a divider in the habitat for several days. Hamsters are nocturnal and do not usually interact with one another outside of mating. Both animals like to burrow, tunnel and play. They groom themselves and chew on toys or cardboard in order to file down their teeth. Hamsters may hiss or lie on their backs if they are frightened.
Habitat
The habitat of a gerbil and a hamster is similar. Use tanks, which should be at least 10 to 20 gallons in size, plastic enclosures with play tubing or wire mesh cages. Mesh cages can lead to a mess outside the cage as the animal burrows and tunnels. Close the top of the enclosure tightly to prevent the animals from escaping. This is especially important with gerbils, as they are good jumpers. The cage should include a food dish, water bottle, toys, an exercise wheel and a substrate. A paper-based bedding will work well. Do not use cedar or pine shavings since the fumes from the shavings can lead to liver damage or respiratory problems. Do not place the enclosure in direct sunlight or a drafty area. Clean the habitat once per week.