I do have a plastic log in there, though, that she likes to climb through. I also have some little plastic people in there, and although I've never seen her play with them, they are not always in the same place. I used to volunteer at the zoo, and that is where I got my sugar baby. When I first got her, she used to make this really strange noise whenever I startled her. It is really hard to explain, but once you hear it, you won't forget it.
Gliders can make a sound like a barking puppy.
I've heard they make it a lot when they are playing with each other. Mine has only done it a few times. A couple of times when she is playing with me, hiding behind the pillows, and a couple of times I have heard it when she is sleeping. Gliders are a lot of fun - but they are a lot of work. I have kids e-mail me all the time asking me to talk their parents into letting them have one as a pet.