The idea was coming from the movement of birds, their wings length is changing when they fly back to their nest. The house space is different from bottom to the top. The narrow on the top allow sunlight goes as deep as the bottom. There are some 1 inch holes with threaded, i want to show an idea about "Customizable" and "replaceable", which is also the core idea of 3D printer technology. with the Threaded connector people can print different color or materials bird-stand(birds can stand outside), transparency hole caps(make it like a small window for bird), and anything you want. Everyone can have their own unique birdhouse and everyone can use their new idea to make it better.Rhino