Problems Importing from Maya to Unity

Hi everyone,

I have a problem when I try to export model to fbx in maya and import it into unity. My problem is in maya, i made animation for the tail of the cat only, But after it’d been imported into unity, the whole body of the cat moved.

Problem(GIF): http://giphy.com/gifs/3og0ILkZwRGExksoCI/fullscreen

help me please!
Thanks!

Is the root bone in Unity set to the root of the tail, instead of the root of the entire hierarchy?