I had that cage for Inky when I first got him, and about a year later he started climbing and actually got his head stuck between two bars at the top. Scared me to death. I was able to get him off because I was right there at the time, but after that I wasn't comfortable keeping him in the cage at all. I ended up getting him a Ferret Nation. If you do use that cage, you will definitely need to block the sides to prevent climbing.