Including their crazy response to catnip, the shape he takes when he's frightened and, of course, his habit of rubbing against you and your guests. When it comes to that last one, there's an explanation that may help you better understand your cryptic cat.

While it may seem like a loving tendency, it can actually be a bit more aggressive than you first thought. That habit is your cat's way of claiming you as his own. Pheromones exist in the glands on his face, and he can transmit them to humans, objects and other cats to mark his territory, similar to how a dog sometimes claims property with his urine. However, a cat's rubbing isn't completely territorial. When he leaves his scent on you, it can also be a sign of comfort. If you smell like him, it means you're part of his pack, and he can rest easy knowing that you identify with him.

Other territorial behaviors include scratching posts and furniture and urinating on objects. If these behaviors become frequent, you may want to consider spaying or neutering your cat, which could help reduce his or her marking tendencies. Keeping multiple cats separate from one another can also help, as it eliminates the need to compete for ownership.