The reason I ask is because of my idiotic CS.
It automatically puts the human skeleton.NIF files on beast races and the humans. What happens when you have a beast race with a Human skeleton you may ask? the tail takes up half the screen...You can walk through it but it goes from the rear end of the Argonian/Khajit to the north point marker.
On animals it has no .NIF file at all! which is bad...
anyway I have explained this to the best of my ability.
If this is a common thing I am sorry but I have looked everywhere on the forums here and on the oblivion wiki but nothing.