Scientific Name: Meriones unguiculatus
Life Span: 2-3 years on average (up to 8 reported, though this is exceptional!)
Size: body about 4 inches long, tail another 4 inches.
Appearance: fairly small rodents with long furry tails that have a little tuft of fur at the end. The wild type coloration is "agouti", where each hair is banded with gray, yellowish, and black, with off-white hair on the belly. However, through selective breeding, several lovely color variations are available.
Habits: Mongolian gerbils are not nocturnal although they are sometimes active at night; they go through several sleep/active cycles in the course of 24 hours. They are very curious and will explore anything, and can be quite entertaining. To get a better understanding of gerbils, see Gerbil Behavior.
Social Behavior: gerbils are social animals, living in colonies in the wild, so do not do well as a solitary pet. Keeping a same sex pair (litter mates usually do well together) is much preferred. However, if you have a single older gerbil, it can be difficult to introduce a new one as they are quite territorial. Some hints on formal introductions can be found in "How to Introduce Gerbils."
Temperament: being social creatures, gerbils can become quite tame. They generally have a pretty agreeable temperament and are generally only inclined to bite if feeling threatened.
Important! Never pick up a gerbil by the tail.
For a pair of gerbils a cage about 12 inches by 24 inches (by 12 inches tall) is a good minimum size, but since gerbils are active, a larger cage is better. Glass aquariums can be used and are favored over wire cages by many owners. Aquariums allow a deep layer of bedding so the gerbils can burrow. A secure mesh lid is necessary to prevent escapes and allow ventilation. Wire cages can be used for gerbils, but they do have a tendency to kick the bedding out when the burrow, making a mess, and they sometimes chew on the wire resulting in sores on their noses. For wire cages, the bar spacing should be no more than 1/2 inch. Plastic cages do not hold up to the chewing habits of gerbils.
A fairly thick (2-3 inch) layer of bedding in the cage provides a good base and allows the gerbils to dig a bit. Avoid cedar or pine shavings; aspen is fine to use as are a number of other newer pet-safe beddings available now. See "The Problem with Wood Shavings" and "Top Ten Alternatives to Cedar and Pine Shavings" for more information.
Nesting material that the gerbils can shred and use to line their nests is also a good idea. The nesting material sold in pet stores is not ideal for this as little feet can get entangled in the strands. It is better to use simple white facial tissue which you can shred into strips for the gerbils, or paper towels and/or grass hay.
Gerbils need a nest box to feel secure; they will hide out in it and use if for sleeping. A sturdy wood or ceramic nest box is preferable to plastic since the plastic will quickly be destroyed by chewing. The wood will likely get chewed to but tends to last a little longer. Clay flower pots are another possible choice.
Provide lots of materials for climbing and enrichment, such as thick pieces of wood, stable rocks, ladders, ramps and platforms. Toys should also be provided that are safe for chewing (i.e. not plastic or with small bits that might be ingested). Wood toys or simple blocks of wood, branches, hay, wood and rope parrot toys, and small cardboard boxes are all good choices. Toilet paper tubes, though quickly destroyed, will likely be a favorite toy.
A water bottle, with a metal spout, can be hung on the cage. A fresh supply of water should always be available. Heavy ceramic food dishes are the best choice since they are harder to tip.
You can consider getting an exercise wheel, but get one with a solid surface to prevent injuries (some owners modify the typical hamster style wheel by applying tape over the wheel to provide a solid surface). There should be no place for the gerbil to catch its tail. You might even want to try something a little different like the Flying Saucer.
Diet should consist of a good quality prepared gerbil diet supplemented with a loose seed mix and a variety of other foods. See Feeding Gerbils for more detail on appropriate foods.
Generally, frequent handling will keep a gerbil quite tame. If all else fails, bribery with sunflower seeds can help make a gerbil more amenable to handling. For more on handling gerbils see "Taming and Handling Gerbils."