Probably the most ideal cage for these mice is a good sized aquarium with a tight fitting lid, and this is especially a good idea if they are being kept in a location where temperature may be a concern. A reptile heater can be attached to the bottom or back of an aquarium to provide radiant heat, and the glass sides naturally help to protect against cool draft. Two mice can comfortably live in a 10 gallon, but for any more than that a 20 long aquarium would be a better size. You can, of course, go even larger, just remember that length and width is far more useful than height to them.
Spinies are absolutely fascinating to watch in a SAM or Crittertrail cage set up and will entertain you for hours chasing each other through the tubes. In fact, we feel that they are almost ideal for these tube cage systems, as these little desert mice have incredibly low waste and smell, and in a reasonably large cage you can comfortably go a month between cleanings with their cage staying clean and having virtually no odor. Considering the effort that can be involved in breaking down and completely cleaning an extensive set up of any of these types of cage, we definitely prefer once a month to a minimum of once a week! As with any rodents though, they DO chew and CAN escape, so extreme care should be taken to secure lids and watch for any holes that might be chewed in plastic tubes or caging. We have yet to have any problems with holes, although we have noticed some minor chewing which has been largely aleviated by providing wooden chew sticks. Typical beddings sold for small animals (NOT cedar!!!) work wonderfully for spiny mice, whether shavings or the pelleted beddings.
Under no circumstances should a single spiny mouse be kept as a pet. They are extremely social animals who naturally live in large groups and are very socially interactive. At the very least, two animals can do quite well together and require no more care or space than one would. The added benefit of keeping two or more mice together, beyond their happiness and health, is getting to watch the wide range of fascinating social interactions that take place between them. With their extremely social nature, two males can even be kept together quite comfortably if introduced at a young age, and almost any combination of mice will live happily together if introduced into neutral territory (a clean cage with fresh bedding) and given plenty of space.
The biggest concern in any grouping of spiny mice is overcrowding. If you have too many mice in too small an enclosure, dominance fights can quickly become fatal. Especially watch for bite marks or pulled out hair on the smaller members of the group, as this is a sign of such fights. If you see any of these signs or witness fighting you need to immediately separate the smallest two or three animals into a second cage, or move the entire group to a larger enclosure, to prevent severe injuries or fatalities.
In addition to plenty of space, these very busy, curious, and intelligent creatures need things to do. Running on a wheel is almost always a favorite activity, and provides needed exercise. Grass or wood huts, chew blocks, things to climb on, and tubes or tunnels to run through are all good to keep your spiny mice busy and happy. While they can be happy left in their cage with only the companionship of their own kind, spiny mice are very clever, and one of the more easily hand tamed small rodents. With regular handling they can learn to enjoy interaction with their human, and even come to recognize certain sounds and perform simple tricks.
While easily hand tamed to be calm and gentle pets, spiny mice do require regular handling to stay friendly. Animals who are not handled frequently will be more hesitant to accept interaction with their human, but even left to themselves they are not aggressive and will almost never bite. Spiny mice who are not used to handling should be picked up by carefully cupping your hands around them, NEVER by grasping their tail, as it can easily be broken off and will not grow back. It is important to be careful when holding your spiny mouse. They are very fast animals and have no understanding of how high they are or how dangerous a fall could be if they slip from your hands. Not only is there the danger of your mouse escaping and getting lost, a fall to hard floor can easily be deadly.
As with most rodents the diet of spiny mice is primarily seeds and grains. Our food mix consists of a basic hamster or gerbil seed mix supplemented with a little wild bird nut and seed mix, cracked wheat, rolled oats, and some grain based breakfast cereal, but spinies can do well with the addition of any of these to a standard seed mix. Beware a diet too high in nuts and sunflower seeds. Spiny mice suffer from very few health problems, but diabetes can occur in animals who are fed an improper diet too high in sugar and fat. In addition to their main food mix, spinies need extra protein, which can be provided by the occasional addition to their diet of dog or cat kibble that is high in protein and low in fat. They will also enjoy occasional treats of fruit and vegetables which should be given sparingly. Although they are desert animals, spiny mice still need to have fresh, clean water available at all times, and do well drinking from either a bowl or a bottle, but a water bottle will need to be protected or positioned so it is hard for the mice to chew, and a bowl can be kicked full of bedding during play time.