You need to keep your Sugar Gliders cage area clean for the both of you. Numerous things cause odors that you may smell, and the most common is from the break down of urine & feces. When the fecal matter breaks down, ammonia is created. Another odor is caused by toys or other objects that you have in the cage area. The final odor would be that of a typical Sugar Glider marking odor.
To control odor, you can do several things. The most obvious is to change the bedding frequently. Some types of bedding will not require changing as often as others. The best way to maintain bedding is to completely change the bedding at least one a week while spot cleaning on a daily basis, more often if you have more than one Sugar Glider. It helps to use bedding that absorbs the scent. DO NOT use chemically treated materials since the Sugar Glider may chew or carry these items in their mouth and can ingest the toxins into their system.
There are different types of air freshener on the market to help keep your air clean. Some just make the air smell better by adding a fragrance to the air thus covering up the odor. Some actually neutralize the smell in the air. An Enzymatic odor remover from your local pet store will neutralize any odors in the cage. You can spray this on the cage, branches, or anything else that your pet might come in contact with.
Try different things, but the best way to make sure that everyone is happy is to make sure there is adequate air flow, change their bedding often, and use something to neutralize the odors. Check to see if what you buy is harmful or toxic to animals before you spray it in the air you and yours Sugar Glider will breathe.