That's such a great idea! There's no accidentally stepping over those walls!I saw something you might like...
View attachment 306607 View attachment 306606
I've had a quick search and found an Amazon link...
https://www.amazon.com/Niteangel-Ha...+wall+hamster&qid=1559772904&s=gateway&sr=8-7
Definitely have to get me some of these.