a C&C cage. I have 3 children. (Ages: 5, 4 and 3) They are VERY mechanically inclined & inquisitive. It doesn't take them very long to take apart almost anything you give them. I was thinking of using a wooden base beneath the grids and using those "U" shaped nails to attach the grids permanently to the wood. Then, the whole top would be affixed in a manner that would allow me to easily remove it for complete cage cleanings. That way I could lift the coroplast out. The sides would use connectors AND plenty of wire ties. I would still use the same locks I have on my pet store cage to keep them from lifting the top. I'm not sure how to incorporate a 2nd lvl though. I'm thinking it will end up bring a 2x1 "loft" or "shelf" for hay & stuff.