Or a shoebox house! Makes a nice hide and has a flat roof. Turn a shoe box upside down and cut a door in it. Or if you want one with a removable roof, leave the shoe box right way up with the lid on and cut the floor out, then cut a door in it. Might not be too glamorous but it would make a good house/hide, and if you pile the substrate up round the outside and put a tube over the door you won't see much of it anyway
