Habitual Over-Grooming

So- some backstory on all this. I've had my female glider for about over five years now, and she was purchased with a same-aged female from the same breeder. Her cagemate however had a seizure and died about a week into owning her, and despite rushing her to the vet there was little to be done for her. That left me with the singular glider (and the subject of this thread). I had to wait a few months before anyone had any young females to be her cagemate, so in the meantime I did my best to fill the void of having no companion- bringing her to school with me under my coat, hanging out with her at night by sitting by her cage.putting my hand in her cage, taking her out for lots of playtimes, etc. This sugar glider grew extremely attached to me because of all this and to this day still won't really tolerate any other people but me. Eventually I did get her a new cagemate and after a rough introduction they've been living together just fine, for about 4-5 years.

In these years I've noticed that my original sugar glider has consistently been an over-groomer, something she picked up when she was cagemate-less. The other glider has never done such. They've gone through two cage upscales, and have toys/enrichment items I switch out and move around fairly often, along with multiple places I hide their food and forage cups, and a wheel. Still, this glider has never quite dropped the habit of over-grooming her face no matter what I try. Over the past few months I noticed the bald spot getting bigger and more pronounced. It tends to grow and shrink, but this is the first time she's been consistently really bald. She's otherwise healthy, eats and poops normally, and active, if a bit neurotic.

I'm mostly just curious to see if anyone has any similar gliders/experiences and if they have any advice on how I can try to stymie the over-grooming a bit or encourage hair growth- I don't think she'll ever really stop to be honest, but any sort of deterrent besides me keeping to needing to drop more money on new toys would be appreciated.

EDIT- here are some pictures in case that helps any?

my over-groomer

my other girl

Hi and

Your babies are beautiful!!!

I see the second glider is starting to groom eyebrows as well. Some call that normal, because it's only slight.

What type of cleaners do you use on and near their cage?

Do you burn candles or use air fresheners, incense?

Have you aquired any new pets recently?

Has there been any environmental changes?

And last but not least, have they been seen by a vet?

Sorry it took so long to get back to you, the holidays tend to keep us occupied sometimes. I will be checking back frequently.

Sometimes something becomes habit after they have been doing it so long. Their fur looks great!

Your babies look adorable!!!!

Very sweet how your little one looks to you!