I was riding my bike for a little bit, and that smell of the handlebars, whatever it is, was on my hands, along with some black marks. Then when I was petting my cat, she smelled my hands and seemed to LOVE it, like she was rubbing against them a lot, trying to nip at them, and acting crazy, when she doesn't usually act like that? What is it about that smell that she liked so much, and is this normal for a lot of cats?