Bug hotel under construction

I had been wondering if there was a better way to use the 'green tubes' that have been protecting the saplings. The trees are now big enough to have them removed and I had been taking them to the tip with a bad conscience. However, visiting the national forest recently I saw them stacked in the undergrowth - presumably to provide a shelter for bugs and small animals. A great idea and SO much better than landfill. My version is under construction:

I have used a couple of old posts and some scrap wood to make the 'backboard'. The one in the national forest did not have this, but I think that it gives much better shelter. I have cut the tubes in half and pushed 4 halves inside each other to give a central hole with lots of snug spaces between the surfaces. Recycled tree stakes hold the tubes in place.
I plan to make it about three time the present height and then cover with brushwood (again my own variation on the national forest version). More photos to follow as the project progresses.