:I'd agree with what Nathan said 100%. A flat sterile pen equals boredom. Give them as much varity as you can. On a side note, when I got my Malaysian box turtles I had them set up in 40 gallon quarentine tanks till I was done treating them for parasites. These were bare bottomed tanks with a raised basking area. One day the male managed to pry the heating unit off the side of the tank and remove the mounting bracket from it. He absolutely loved it and would play with it endlessly chasing it around the tank. When they moved into their permanent quarters it went with him and it remained an endless source of entertainment for him.