In my experience with these guys i found the installation of fresh cut shrubberies such as bamboo and the like(obviously use non-toxic plants) to provide a leafy cover really ads to their sense of comfort and security which lends itself to them exihibiting more behaviors. As for substrate i had been using pottingsoils orchid bark and such on top of newspaper until this madman told me to try simple leaflitter collected from someplace without much chemical pollutants. He actually took me into the hills where we filled countless bags with leaves and sticks and such which he actually put in his otdoor lacie and croc monitor enclosures! What a whack! So i got home and put in a foot deep layer of the stuff and the rouh necks LOVED it! On the same trip he convinced me to try hollow logs in place of the manmade hide spots i was using at the time. Well hell if he wasnt right about that too! They NEVER used the old ones again! And these were all just bug covered out in the woods pieces of old log gathered in dirty old nature. Sure i hosed em off but other than that straight on in. A few months later they were breeding. Thanks Frank!
The leaflitter kept the humidity good though i still hosed thecage once a week or so as the tucson air is rather dry and the logs were the monitors meow so to speak. The cut bamboo was the icing on the cake. Be sure to provide a number of basking spots both hidden and unobscured at various heights. That crazy fellow also got me using basking spot temps around 180 degreesF whIch proved rather effective to no ill result. Hope this helps!
Guy