Why does animating a subview cause its parent view's layoutSubviews method to be called?
<p>I'm doing UIView animation on individual subviews that have a number of sibling views that I don't want affected by the single-view animation. However <code>layoutSubviews</code> is being called on the containing superview when I do the animation, causing the other siblings to be rearranged as well. </p>

<p>(I should explain that I'm doing initial subview layout in the parent view's <code>layoutSubviews</code> method; I only want it to be called the first time I'm setting up the subviews, not when I'm animating them individually later on.)</p>

<p>Why is the parent view's <code>layoutSubviews</code> method being called when animating its subviews?</p>
