I'd go with those saying get rid of the tubes. If any of the blocking material gets damp or soaked with urine, or the ham continues spending many hours in it, the condensation is simply not healthy. Plastic doesn't 'breathe'.....My Syrians use them for transport. That's it. If I block it, they unblock it since its the easiest way between levels. As for making nests for her, hamsters make their own nests. All we need to do is provide the options....an igloo house, a carboard box, see what works. Some just like a big pile of bedding to burrow. A major cause of hamsters getting snippy and frustrated is having their homes being tampered with all the time for whatever reason. I don't have to like my hammies current nesting choices, but if they're healthy and happy? Its their cage after all.....I'll be trying to see if Pook wants to make a large box a new nest instead of his clear spinning ball on the roof....since he seems to poo in it a bit. Last time I cleaned it out, he was fine, and rebuilt it. Now, I'm thinking of removing all bedding material on the wheel floor so it doesn't start becoming a cave and a half of soiled bedding after time.
Also will be moving his cage soon, to a different setup for a number of reasons....he's hitting full growth size now and needs a bit more room. But I at the end of the day, he insisted on his ball/nest ? I 'll have to clean it out every couple of days and replace his bedding minus the poo, and listen to him grumble for a couple hours while he gets everything JUST RIGHT!
Or, he'll fall in love with his new box next? One of the best ways to have a happy animal? Read their messages to you and know what is rightly theirs and respect it. The time to intervene is when their choices are unhealthy or unsanitary in the unnatural environment of plastic/metal/wood/glass cages, or when they can harm themselves. It usually takes us a while with some hams to figure out, okay, if he insists his food bowl be THERE, upside down and useless, his house is a toilet and he sleeps in a wheel ? It's okay, however aesthetically unpleasing it is to us humans who want to see a pretty, neat, organized cage. Not saying you are doing that, but the tempation is there for all of us I think......tsk, he tipped it over AGAIN!!!! Well, unless it needs to be upright? and it makes him happy tipped over? Tain't nobodies bidness if he does!