It isn't a 'must do' but it does give them something extra to climb on. I have it in Monty's cage and it is great to fix branches and vines to so you don't have to make holes in the screen. He still climbs on the screen sometimes, but not often. Here's a pic to show how it is used in my set up. Both my Jackson and Carpet have it in their cages. I love it so much that I am buying some more for my outdoor cages.