New instance coordinates different to stage coordinates

Hi

I'm trying to find the coordinates for placing a new instance of a movie clip on the stage. 

When I manually place the movie clip, the coordinates are x = 216, y = 148 - which is what I'd expect.

But to get it in approximately the same position on stage with code, I have to change the coordinates. The code I'm using is:

var ant = new lib.ant()
ant.x = 135
ant.y = 0
ant.scaleX = 0.15
ant.scaleY = 0.15
this.addChild(ant)

Why is this? What are the coded coordinates relative to, if not the stage?

Presumably the anchor point is the same whether it's placed manually or with code? Could it have anything to do with the fact that the movie clip is scaled?

Thanks for any help.