While Christmas trees themselves are not poisonous for cats, the needles from the tree can be harmful if ingested. Additionally, cats may be attracted to the tree due to its height and the smell of the tree, so it is important to keep a close eye on them to prevent them from climbing the tree or playing with the ornaments. To keep cats safe around Christmas trees, it is recommended to place the tree in a secure location where the cat cannot reach it and to use pet-friendly ornaments and decorations.