mouseenter bubbling

mouseenter bubbling

HTML:
  1. <ul>
  2.       <li>First</li>
  3.       <li>Second</li>
  4. </ul>
JS:
  1. $("ul").on("mouseenter", "li", function() {
  2.       var t = $(this).text();
  3.       console.log(t);
  4. });
Why does this work? "mouseenter" should not bubble!