Scratching The Mesh

[Mochi]

Oi- so my gerbs are currently housed in a 20 gal. Which was almost filled to the brim with bedding. The reason it isn’t anymore is because they have been pawing/clawing the mesh lid, which is a HORRIBLE sound. For some reason they only do it at night..  
 
I definitely have been looking for permanent solutions (like a topper) since I’m thinking they are doing this because of boredom. I am DIYing their topper and right now it’s a bit of a work in progress. All I need before I can assemble it is a bird cage. I tried looking for a actual topper but none of them really seemed right for what I was looking for..

Any suggestions for some temporary suggestions? I will be moving them into another room for now but it won’t be for long since the rest of my house is usually very loud and busy!

All suggestions are very much appreciated!!

[Markpd]

Temporary suggestions to stop them chewing the meshed lid?
Unless they only chew the mesh in certain spots, I think your only option is lower the bedding height. If it's just 1 or 2 spots, perhaps you could attach much finer mesh there (so they can't get their nose through the mesh), or attach (sacrificial) cardboard over it....err under it, if you follow me

Re a topper, how about the top part of an old hamster cage?

[Mochi]

I have lowered the bedding! I also sort of flattened it down? They are more pawing, like scratching their nails against the mesh…. Yes, a top of a hamster cage just might work!! Now to find one!