sounds pouch protective to me which means he/she is scared and or insecure. Try not zipping the pouch closed and roll it down some so he/she can see whats going on. Look for some open environment pouches for in the cage
There's no way to teach a glider not to crab, it's one way they communicate. Move slower when they are in the bonding bag, shorten the neck strap so it doesn't swing around as much when you move. Do things a little differently to accommodate that gliders needs. I wrote the following to help some others with this issue it's long but I hope it helps...
My 4 yr old male was pouch protective when he first came to us, and these suggestions are what I did to address the problems. We have had Simon since October, it is now the end of May and He has come a very long way in that time. He is currently adorning my head under my hoodie...He's my fav hair accessory
First Understand, Pouch Protective is usually fear based, NOT aggression or being mean. Gliders are very small with limited ability to protect them selves. They rely on scare tactics like crabbing, lunging, biting, slapping, hissing to keep predators at a safe distance. YOU my friend are considered to be a threat and possible predator at this point in your relationship. Take a minute and consider your gliders position, imagine yourself to be his size, in a cage that he feels is all his, then imagine a human reaching into the cage.
Gliders are territorial, especially males, The cage is HIS territory and you are intruding on him in his own space. When he lunges at you in the cage he is saying "GET OUT, GET AWAY FROM ME YOUR TO CLOSE FOR MY COMFORT"
Respect the cage and consider it to be the gliders first "safe place" and try not to be so intrusive. Put food in earlier than they wake up, clean the cage while they are a sleep, adjust and change out toys while they are asleep. When they are awake and active just sit by the cage and talk to them, let them get used to your voice. When you approach the cage, talk to them so they know your coming near their space. If they come to the front of the cage to great you give them a treat.
Now lets get into Pouch Protectiveness ( PP ).... I found that with Simon it was entirely fear based. Bonding Bags tend to be deep, and zipped to contain the gliders. The problem for PP gliders is they can't see out of bonding bags very well. The same can be said for some sleeping pouches. Open Environment Pouches ( O.E.P ) are designed specifically for PP gliders. The top and sides of the pouch are open to give the glider the ability to see whats going on in the cage simply by lifting their heads. When a glider can see what is going on, whats making the noise, whats shaking the cage etc... then they realize it's nothing that's going to hurt them. So for your cage, look into O.E.P pouches to help him get over his fears.
For bonding bags... I used the same sort of concept. I made a single layer pouch that has a wide top that can be rolled down, no zipper at all. PP gliders are pouch protective they don't WANT to come out of the pouch, they feel safe in the pouch so a zipper isn't usually necessary. This type of pouch has a few advantages for YOU and the PP glider.
1 You can roll the pouch down and see the glider better so your not blindly reaching into a deep, dark pouch with the likelihood of getting bitten.
2 The glider can see out when the pouch is rolled down.
3. The PP glider can see you giving treats to the more confident female
The one draw back is, you can't really move around to do other things while the PP glider is in this pouch. You can NOT leave him unattended even for a second. So make sure you have a good bit of time where you can just sit and watch tv or something.
This is where using the confident glider to your advantage comes into play. And I will explain my routine to show you how she can help you.
At about 11 am I would gather up the treats, roll down the single layer pouch and take the sleeping pouch out of the cage, bring them to my bed. Get Simon into the rolled down pouch, once he was in there, I would proceed with giving Leela a treat, with Simon being able to see me giving her the treat, and see Leela taking the treat nicely.
Next, offer Simon a treat, with one difference, hold the treat a little farther away from his face. This is IMPORTANT, it is again showing him you respect his "personal space" Let him reach out his neck a little to take the treat so he is meeting you half way. He may slap the treat out of your fingers, or snatch it really fast then recoil into the pouch. DON'T REACT!! Don't flinch or with draw your hand stay right there!! until he is happily eating his treat. Then give the lil girl another treat and repeat.
Keep doing this same routine every day, when you notice Him being a little nicer about taking the treats you can start offering them a little closer to him. Little by little until you can put the treat right up to his nose with no negative reaction. This may take a few days so don't try to rush him on it, take your time.
After treat time Leela would dive into my sweatshirt, Here's where you may have to find what works for you on your own. Your lil girl may prefer the bonding bag but keep the PP glider in the rolled down pouch. It's not terrible to give these two a little space from each other while you are bonding with both of them
The PP one will start getting used to your hands from the treat giving time. And once he seems a little more comfortable with that you can begin to pet him in the rolled down pouch. I found waiting for Simon to go to sleep worked the best. You see the "scare tactics" mentioned earlier are to discourage predators from coming to close.
However, those tactics are useless once the invisible barrier is already breached. Meaning if he is a sleep, and wakes up to your hand already petting him, he most likely won't lunge, slap, crab because your hand is already in his space, though he still may try to bite. If he still does any of these things just keep your hand right there and don't remove it until he stops, unless he is biting the living hell out of you.
If you remove your hand you are telling him his scare tactics are working!!
To help minimize the biting don't pet him with your finger tips!! Close your hand and sort of make a fist. Pet him with your knuckles until he is more used to your hands in his space. When you hand is closed your skin is tighter, it's harder for them to open their mouth far enough to bite a knuckle and with your skin being tighter the bites down't hurt as much.
Once he gets used to being petted with your knuckles and stops showing any negative signs it's safe to proceed with petting him with your finger tips...
Once you are at this stage, you can start "cupping" your hand over his back, he may tense up a little, and it can make them to warm after a while so only do this for a few minutes at a time, then let him just "be" in the pouch on your lap. Then proceed to pet him and start working your way to the top of his head.
When you can do all this, with no crabbing, lunging, etc... Now you can start Unrolling the pouch, One roll only for the first day, to let him get used the pouch being a little deeper. After a week or so Unroll it one more time and so on and so on until the pouch isn't rolled down at all. While you are doing this try to have something with a zipper near by and zip and unzip it so he gets used to the sound.
At this point he should be ok to start going into a regular bonding with the girl. This is NOT a fast process so please do not rush to the next step until he shows signs he is ready to do so. Pay attention to his body language you will start to see when he is comfortable with something and when he is not.
I can offer Simon ANY pouch now, he voluntarily goes inside with no more issues. He is also now at the point where I don't NEED him in a pouch, he is usually in my hoodie of my sweatshirt now, which is his fav spot aside from on my head lol. The hoodie allows him to see everything if he wants to, and to come out onto my shoulder if he wants to see what I'm up to which he does everytime I go to the kitchen go figure lol.
I apologize for this being such a long post, but I did say it was detailed lol. The main thing aside from showing them you respect your space is to be confident and calm any time you interact with them. They can sense your fear, or anxiousness and that does not give them much confidence IN YOU. I hope this helps and please keep us updated on how things are going. Keep in mind all gliders bond differently, what works for one may not work for another. So sometimes we have to adjust how WE are doing things to accommodate the gliders individual needs.