Reptile Screen Cage

have 2 cats and only one of them sits on top of my snake's cage ALL THE TIME! The top is like a screen and it's getting somewhat stretched out from my cat laying on it. I'm afraid one day it's going to break and my cat will fall in and get the snake. I have to put my cat in the other room if I want to get the snake out cause she goes ballistic trying to get the snake! Any suggestions on keeping my cat off of the top of the snake cage?

I asked this in the cat section, but people are telling me to cover up the top with foil and mats...they clearly don't understand that my snake has to breathe! So I thought the reptile people might have better answers! Thanks!
I have a 6 foot tall cat tree with many shelves. They both like it, but my calico prefers the snakes cage. I cannot put the cage in another room and keep the cat out. I have a 1 bedroom apartment and it's not possible. I just have to figure out something else.

Thanks for all the suggestions so far though!