It is almost like an impatient kind of thing.
I agree, it is basically an inpatience issue. That is why I said that in my first post. I do not mind my mare doing it and I have been unable to break the habit with her. It does not bother me that she does it as she only does it when I am going to feed. I do not even notice it half of the time when she does do it. I guess it comes down to how annoying the habit is to the owner and on how worried you get about it.