Mouse Head Moving Whole Body?

Hi!
I’m sure this is really simple for most of you, but I am having a problem Isolating the head of my model so that It moves without moving the whole body with it. could someone help me please?
-ross

Attachments

mouse5.blend (427 KB)

Thanks for the reply! I did check weighting.
I think it is a problem with how I have the bones parented. If you open the file and rotate the head bone. the rest of the body comes along for the ride. I need the head to pivot where it joins the spine. does that make sense?

ah, you can change the relationships of the bones over in the bone properties panel I think. ( still a bit lost in 2.5+, so you might have to check that ) But, best policy is to always start at the base of the spine, so your first bone would be the tail bone, and all bones are children of that bone.

that fixed it, thanks!