You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <allfileusages gafcontinue="Bed_bugs_on_a_blue_sheet.jpg|47" />
  </query-continue>
  <query>
    <pages>
      <page pageid="33" ns="0" title="Septic Tank Cost" />
      <page pageid="52" ns="0" title="Bed Bug Eradication" />
      <page pageid="70" ns="0" title="Bed Bug Sniffing Dogs" />
      <page pageid="77" ns="0" title="New York City Bed Bugs" />
      <page pageid="134" ns="0" title="Mold Common Facts" />
      <page pageid="139" ns="0" title="Mold in your home?" />
      <page pageid="143" ns="0" title="Black Mold Facts" />
      <page pageid="180" ns="0" title="All About Bed Bugs" />
    </pages>
  </query>
</api>