There should be one more hiding places than you have degus so that they can always have somewhere to hide. Having more hiding places will reduce fighting as they will be able to hide when they want to and won’t feel the need to defend their spot.
There are multiple options for their bed: you could go with a wooden bed box, a hammock or a plant pot. Any enclosed space in which they can feel safe would be suitable. Your degus may have a preference, for example when we first got the little guys we gave them a bed box, but since we gave them a hammock they’ve taken to sleeping there in warmer weather. If using anything that can be chewed this will need to be inspected for damage and repaired or replaced as required. The little guys have chewed through the strap of the hammock before, which gave them a shock when the hammock suddenly moved.
The degus should always have access to a wheel. This should be at least 12 inches in diameter as a minimum as anything smaller can cause damage to their spines. Possible materials for the wheel are metal, plastic and wood. The wheel should be solid in order to avoid injury to paws and tails. I wasn’t able to find a solid metal wheel with a large enough diameter so I made a wheel using a cake tin, lazy susan bearing and rivet gun using this guide.
Both of my sets of degus have an upright wheel in their cage, the little guys also have a flying saucer wheel.
In order to clean themselves degus require a sand or dust bath – they should not be washed with water unless there are specific circumstances that require it, such as a bad reaction to a topical medicine. In the rare cases where a degu does need to be washed with water something such as a gentle baby shampoo can be used.
Either sand or dust can be used, my guys started off with sand baths and when later presented with the option to choose between sand and dust the vote for dust was unanimous. As the dust is finer it can work it’s way through the fur to the skin better and perhaps does a slightly better job of cleaning, however it also makes quite a mess, even with an enclosed bath, and so long as they have a sand or dust bath I wouldn’t worry too much about which one they are given.
It is recommended that the sand/dust bath is not left in the cage permanently as the degus will begin to use it as a toilet. The bath could be put in the cage for 20 – 30 minutes a day, or the degus could have access to it when they’re out for a run. Personally I leave the dust bath out so that they can have a bath while they’re out for a run if they want to, which they don’t always. A bath every two – three days would be sufficient, if they bathe too frequently this can cause their skin to dry out.
It is possible to toilet train degus, so a bowl with a little sand could be left in the cage to be used as a toilet.
In the wild degus live in burrows and where possible they should be provided with the opportunity to dig. This is difficult to incorporate in most store bought degus cages, it could be done more easily if you were building your own cage, however this is time consuming and impractical for most people. If there would still be enough running space in the cage you could provide a small tank or plant pot in which the degus could dig, although finding one large enough for the degus to be able to dig in properly might then encounter the issue that it won’t fit through the door of the cage. I’ve tried to provide a tank in which my guys could dig while they were out for their run, however they were always more interested in running around than digging.
Other things my guys have in their cages include hammocks, logs, branches, tubes and tunnels.