I recently noticed a bald spot on his head that showed up at the beginning of this week. I was wondering if it is anything to worry about.

He is about two years old and in the time that I've had him, 1 1/2 years he's never had this spot, so it is making me worried.

So I'm wordering if it is anything to worry about or not?

It appears that he is over grooming.

Gliders do this most often when they are lonely and/or bored.

Have you considered getting him a cage mate? Gliders are colony animals and really do need a companion to snuggle with while sleeping, share food and grooming activities and as a play mate at night when Gliders are awake and active and their humans need to sleep.

You may also want to change things around in his cage and add some toys for him to explore at night.

If his behavior has changed in other ways as well, a well check up with a glider experienced vet would be a good start to make sure he is healthy.