That's a really good idea actually. I am going to pick up some foam tape (the thick kind) to seal up the edges so she can't get between the lid and the tank. The original lid I had on the tank (the one that came with the tank), the screen fell out of because the fat cat got into my room. So I had to get another lid with hinges in the middle. Unfortunately it is like half an inch too large and doesn't lay flush on the top of the tank.