Well, as an expert reindeer, I can tell you that cats are notorious for being curious and mischievous. If you want to deter them from climbing your Christmas tree, you can try a few things. First, make sure there's nothing interesting at the base of the tree that would attract the cat's attention. You could also place a few physical barriers around the tree, like empty boxes or a tall piece of furniture. Finally, you could try some cat-safe deterrents like aluminum foil or citrus oils.