How to make a detolf lid

[youaremysunshine]

So I am purchasing a detolf for my gerbils (hope to get it this weekend!) and I have worked through all the details except one. I do not know how to construct a safe lid, that will not completely block my line of sight. Right now, I have a tank topper on my 10 gallon that snaps onto the sides, made withmetal bars. I really like this set up because I can poke my fingers in and say hi. I was thinking of building a tank topper sort of thing for the detolf, but I have two questions. A) how would I secure the topper onto the cage, and b) how would I make it so that they cannot chew the wood? Even if I ended up making a flat lid like the one that Erin's animals did, how would I be able to secure the lid, because my gerbils are little houdinis. My moms convinced they figured out how to open their cage topper, so I have to put a weight on the top to keep it shut!

[BoxRAddict]

Instead of a single lid, I made two seperate matching lids, this is how they turned out...



It's for a hamster, not gerbils, but for each lid, I used:

2 longer pieces of wood
2 shorter pieces of wood
4 flat joints with nails to attach them together

then I staple gunned the mesh to it

Here is a view of one of the from the bottom:

[youaremysunshine]

That is most likely what I will end up with, I am just scared that it will not be heavy enough, or they will chew the wood up.