thought I'd pitch in here... My cat LOVED to get on top of my snake's enclosure when she was in a 10 gallon, whether it's because of the small moving wriggling animal he'd love to eat, or he felt the heat from the hot side and loved basking. However, I HATED this behavior personally; so when I moved Kira into a bigger final enclosure, I put a layer of double sided tape on the top of the enclosure, just covering the plastic doors - the mesh is still uncovered so that ventilation can happen and I can still open the plastic doors, but the cat won't jump up because he doesn't want to get his paws stuck!

it created a situation of safety that the snake has her own personal escape, and the cat has found another, further away perch from which to observe without barging into Kira's personal space. I'm definitely not telling anyone how to live their life, just thought this would be a good time to share my own experience with my overly-curious cat!