Answer:
Stealthy as a shadow in the dead of night, cunning but affectionate if given a bite. Never owned but often loved. At my sport considered cruel, but that's because you never know me at all.
My first is an insect; my second is a border; my whole puts the face in a tuneful disorder.
When the horse strokes the cat, the wood begins to sing.
He has one and a person has two. A citizen has three. And a human being has four. A personality has five. And an inhabitant of earth has six.
I can ruin your day, or darken your life. And while I'm expected, I'm never alright. I'm bad for business, and worse for your hair. Wherever I am, there's something not there.
I'm the source of all emotion but I'm caged in a white prison.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?