If you could post a pic that would help....
I'll post a couple pics of mine...it's just a small $24 tent from WalMart.
It has a plastic bottom, sides are blue then a gray tent material, then the top is mesh. Mine cannot climb the sides, it's too slick, nothing to grab onto...I got a bird ladder from PetSmart that I just lodge against the side to let them climb, also take other things in. I will also put them on the mesh so they can climb, but beware,...they will launch to you! Facehugs are a real possibility!
I attach fleece strips from the tent seams (pic)
This pic shows the bottom & the blue & gray tent sides
This pic shows the mesh