i have never posted a reply before. this is to the person who asked about building ferret cages. we built one , and used Plexiglas on the whole length of 2 sides. we really like it, as does our fer-fer. we can see him, and he can see us. it is really nice. consider. we used some rabbit wire.(on top front and back.) we made it three stories, and ladders to get to each one. we used pieces of linoleum to cover plywood floors(easy to keep clean). good luck! you will enjoy building for your little friend! [Posted in FML issue 3375]