Navigation Menu not working Bootstrap

Hi I am getting error in my wordPress Bootstrapped menu first of all it there is submenu in the about us when I hover my mouse it does not open. secondly on mobile screen responsive button is not working and displaying menu list already without clicking

here is my site: http://www.abiglittlebiz.com/trevelle/

Here is my code:

   <nav class="navbar navbar-inverse">
      <div class="container">
        <div class="navbar-header">
          <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
            <span class="sr-only">Toggle Navigation</span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            </button>
          </div>

        <?php 
    wp_nav_menu(
        array (
            'theme_location' => 'primary',
            'container' => 'div',
            'container_class' => '',
            'container_id'    => 'navbar',
            'menu_class' => 'nav navbar-nav'
       ) 
    ); 
?>
            </div><!--/.container-->

        </nav>
    </header>