I do not suggest putting duct tape (or any kind of tape) in your enclosure. They can get stuck, rip off healthy scales and are a nuisance to clean properly. Plus - the design of that tube does not give the bp much sense of security - the two open ends are not conducive to a happy bp. Get yourself two matching cereal bowls and cut a doors in them, much more secure, only one door and they are much easier to clean - just run them through the dishwasher!