title: Why does a rect require width and height attribute in Firefox?
body: <p>In the following example I created a blinking eyes animation using CSS and an SVG: <a href="http://codepen.io/JamesTheHacker/pen/oLZVrY" rel="nofollow">http://codepen.io/JamesTheHacker/pen/oLZVrY</a></p>
  
  <p>It works fine in chrome, but on Firefox the eyes do not appear unless I specifically provide a width and height attribute on the <code>&lt;rect&gt;</code>.</p>
  
  <p>Without the attribute the eyes are not visible. If I add the attribute the CSS <code>height</code> animation has no effect.</p>