hi i just got a greek tortoise and set up his tank with a forest looking tank surround on3 sides like you use on a fish aquarium.when my greek is active he goes to one corner and tries to climb up the side he doesnt see clear glass as it is covered help explain why he just goes to that corner . one time he did it for an hour i kinda got worried cause he just kept hitting his face is he trying to tell me something ?is there something i should change or add?some help please.thank you