Cats are naturally drawn to the scent of pine trees and may want to explore and climb them, which can be dangerous for both the cat and the tree. To keep cats away from the tree, you can try spraying a mixture of water and citrus essential oil around the base of the tree. Cats tend to dislike the scent of citrus and will likely stay away. You can also use a motion sensor air freshener or spray, which will emit a strong scent when it detects motion. This can be an effective way to deter cats from approaching the tree.