Most of the knowledge I collect about sugar gliders comes from observing and then mimicking nature. What would the parents do with this little one in this situation? If they were bit by one offspring, I can almost guarantee that they would bite back and establish a parental dominance. I have seen mommy push baby's head off of her nipple, push baby out of her pouch, I have seen daddy sling baby off of his back, I've seen daddy grab baby's head with both hands to hold her still. And almost always, following these behaviors, they follow up with positive reinforcements, such as licking, nosing, grooming, cuddling.
I have had my success with biting essentially by using negative reinforcement followed immediately by positive reinforcement. This mimics exactly what parents do with their offspring, what an alpha male does to establish dominance with females, and what pairs do when they argue/fight. They let it out, perhaps fiercely, and then they come back together peacefully once one of them accepts submission.
First of all, one has to understand the difference between a bite and a BITE. These animals bite each other constantly. Dad bites baby often on her legs and back and bottom, mom and dad bite each other in the sleeping pouch, ... BUT, these are nibbles. The animals use their mouths for everything they do; to groom, to convey affection, to test, to motivate, to force submission, and parents use it to affirm and give attention to young. So often a light nibble, that may startle you, is not meant to hurt. I sometimes think that young biters, as is most common, are at a stage where they have learned to bite everything first to test it, to see if it is alive or food, or to test their relationship with it, ie: "does it mean me harm". This is a learning process for them. Unfortunately, somewhere along the way, especially with the mistreated and rescues, some of them go radical with the action and they learn to bite hard and fast and without any reason. I dont think it starts because they are scared, I think it grows into that behavior especially when they initially scare or anger their unprepared owner.
Ok, so your animal bites you HARD and for no acceptable or known reason. When I am bit, I make a quick decision as to what just happened and why. If the bite was an attack, and I am sure of it, I commit to acting and do the following procedure immediately regardless of how much more I am being bit along the way.
NOTE: A lot of the community at large will firmly object to this, so please simply consider it additional information and something that works for me. I believe that most people with gliders forget that these are WILD animals and their INSTINCTS have not been bred out of them, instead, they have been INBRED into them, especially here in the US. I believe that doing ones best to reproduce what happens in nature for these animals is the best thing one can do while keeping them caged, and this extends to all facets including diet, pairing, mating, parenting, ... and therefore my other ideas, including diet, follow this concept and would be extremely unpopular as well.
BITER PROCEDURE:
When bit hard by a kept sugar glider, immediately grasp the animal HARD with one hand so that the back is to your open palm. While closing your grasp around the animal, thrust your thumb up along the chest of the animal until it reaches the bottom of their jaw. This hold will disable their body and head and not allow their teeth to reach your skin. Hold the animal FIRMLY until it finally stops crabbing and trying to get away. This could initially be a VERY VERY long time. The intent here initially is to disable the animal while protecting yourself, and to then let it wear itself out while crabbing and trying to bite you. You must hold this position until it stops verbalizing. If you release grip while it is verbalizing the 'mental' procedure will be broken, the animal will think it has won its freedom and nothing will have been learned. When it finally stops verbalizing, it has accepted its predicament and is more open to accepting submission. If you release a little very lightly and the animal will squirm to get out and will crab again. I will often retighten the hold until the animal relents once more. This is to reinforce the dominance and their submission. At first, when finally releasing the animal for real, do not do it slow. You do not want it to attempt to bite you at this time while fleeing, if it does, it will have won and nothing will have been learned. If you can release the animal to your arm or the cage, it will run away, find a place to be safe and will consider what has just happened. Releasing the animal is one step of positive reinforcement. Do not leave it alone at this point, it needs your continued attention to reinforce the procedure. Immediately follow it up by offering a treat by hand. I use sunflower seeds or mealies for this. And I will keep offering them after this procedure until the animal will no longer take them from me.
When the animals begin taking food from you and eating in your presence, they are learning to be comfortable with you. They are learning that you are a care giver and do not mean harm. Unfortunately, the procedure will need to be repeated over time as you are bit, however, you will find that the animal will crab much less and will relent much sooner when doing it again and again. It will learn that a bite always causes the grasp and it will simply stop biting. The last time I had to do this with mommy, she didnt even crab, she just instantly relaxed in my grasp, accepted the adjustment and stayed calmly in my hand when I let her go.
Naturally, this procedure is stressful to the animal, however, I have found it successful in establishing dominance, much like gliders in the wild would establish dominance, and it is much preferable to allowing yourself to be bit over and over and allowing the animal to become increasingly skiddish at being handled and then eventually finding itself in a rescue and unwanted.
The sugar glider pictured below is a mean female biter that came in as a rescue from a very bad and scary exotic animal environment. I have found that females are the worst and the hardest to break and she is beyond that. In the photos, she is being held with different levels of force and she is at the point where she no longer crabs when being restrained and doesnt seem afraid. She does still try to bite for freedom and she gets an immediate tighter hold adjustment as a "no no" at the attempt and then the hold is relaxed again. She specificlly will require much more of this conditioning in order to enforce the end result, but she will eventually take to it.
Disabling a sugar glider's jaw
Disabling a sugar glider's jaw
Disabling a sugar glider's jaw
Disabling a sugar glider's jaw
Disabling a sugar glider's jaw
Over time as they learn that biting results in the hold, I will catch them approaching with opening mouth for a bite, but then they withdraw before making contact. It is because they remember. The stress of the procedure has formed a solid memory in their mind. And now I can pet them, hold them, grab them, hand feed them, play with them, and all is well, and my cage kept animals are happier and unafraid and so am I.