Buying a cage is the largest expense in keeping a gerbil and it is important to provide the best and largest cage for your gerbil that you can. However, it is possible to make a cage yourself for your gerbil from relatively cheap items.
Gerbils are sociable and will live happily in pairs or groups of mixed or single sexes. Gerbils are best introduced at a young age particularly males. When buying two or more gerbils to live together it is not necessary to get gerbils from the same litter but they should be roughly the same age and size (and sex if you do not want to breed them) and should have been living in a group community when bought. They may squabble a little when first introduced but the squabbling often sounds worse than it actually is and is just their way of establishing who is the boss. They are best left to sort this out unless serious injury or prolonged non-stop fighting occurs. Occasionally a very dominant gerbil may not accept living with another but this is rare.
There are a variety of gerbil or rodent cages available from pet shops or Online Pet Stores which are suitable for gerbils. The most common type of gerbil cage has a plastic base and a rigid wire top. The wire top can be unclipped from the base making it easy to get the gerbil out of the cage or to clean the cage. Similar cages with two or more floor levels are also available with ladders which allow the gerbil to climb up and down between the different levels. These plastic base, rigid wire top cages are lightweight, durable and relatively cheap. However, you should check the secureness of any doors on such a cage as one that is opened too easily may be pushed open by the gerbil. A cage with a shallow base will allow woodshavings to be kicked out of the cage and so it is best to find a cage with a deep base. The disadvantage with these type of cages is that they are not draughtproof and so it is important that this is considered when deciding where to put the cage.
Aquariums can also be used to house a gerbil. These are draughtproof and relatively cheap but glass aquariums can be awkward to clean because of their heavy weight. Plastic aquariums however are much easier to clean being lighter but the sides tend to become scratched after a time. Aquariums make ideal cages for pregnant gerbils, nursing mothers and baby gerbils. A water bottle can be fixed to the side of an aquarium by using adhesive Velcro pads or some water bottles are designed to be hung and these can be hung from the top of the aquarium. It is always best to ensure a lid is fixed to an aquarium - this will ensure nothing is accidentally dropped on the gerbil, and will also help in preventing the gerbil to escape - most full grown gerbils are able to escape from aquariums which do not have lids. A wire mesh top is preferable to a solid lid with airholes as this prevents the build up of condensation.
Gerbils love to dig and so an aquarium provides an ideal environment for them to do this if filled with a deep layer of woodshavings. Pushing tunnels or cardboard tubes down into the sawdust will encourage the gerbil to dig deep and burrow deep under the surface.
Cages made totally from metal are rarely seen these days and have a tendency to rust.
Home-made cages can be made from a combination of wood and wire mesh and a piece of perspex - the base, back and two sides made from wood, a front perspex window and a wire mesh top within a wooden frame hinged at the back and with a little securing hook at the front. The disadvantage with this type of home-made cage is that the wood soaks the urine and so frequent cleaning is needed to keep the cage free from smell and gerbils do tend to gnaw the wood and so these types of cages may need repairing from time to time.
Home-made cages can also be made from plastic storage boxes with wire mesh tops and these are cheap to make, easy to clean and draughtproof. The disadvantage is that they are usually solid coloured and so do not allow you to see the gerbil unless looking from above.