I think you are right about this. Tokay do show totally different behavior in larger tank. When I first got my female 2 months ago, she was in a 10 gallon; then i bought a 29 gallon for her, and now, she seems to be enjoying it..walking and jumping around. Tokay are animals meant to roam some around; males and females have territories that they defend against other intruders. And I think it's partly due to the way i feed her also. I change from putting crickets in a small tray to feeding ones that can jump around, and she seems to enjoy hunting them.