My vivarium is not nearly as nice as many of yours, but I recently decided to add some fake vines to 'green up' my otherwise plain tank. Wilma, my two-month old corn snake, is usually only out of her hides at night, but literally minutes after I put the new vines in, she's out roaming and climbing mid-day. I didn't realize how much she would 'enjoy' them. Here's a picture of the vivarium before I added any green; functional but boring:
And here's a picture after. Can you spot her?