Bootstrap grid not stacking

I have written the HTML below I am using bootstrap 3.3.7, I have been bushwacking through the web and tweaking CSS and jQuery for 3 days now and I am not finding a solution.

I cannot get the grid to stack in mobile view. It worked when I coded the layout and then something unknown to me happened and I cannot repair it. Please help.

    <div id="idport"> <!--Portfolio-->
        <h2 class="mheading">Portfolio</h2>

        <div class="row" style="margin:0">
            <div class="col-xs-2 thumbnail">
                <a href="#" Title="Some website">
                    <img src="Spacer.png" alt="Some website">
                </a>
                <p>This is a title</p>  
            </div>              
            <div class="col-xs-2 thumbnail">
                <a href="#" Title="Some website">
                    <img src="Spacer.png" alt="Some website">
                </a>
                <p>This is a title</p>                      
            </div>
            <div class="col-xs-2 thumbnail">
                <a href="#" Title="Some website">
                    <img src="Spacer.png" alt="Some website">
                </a>
                <p>This is a title</p>                      
            </div>
            <div class="col-xs-2 thumbnail">
                <a href="#" Title="Some website">
                    <img src="Spacer.png" alt="Some website">
                </a>
                <p>This is a title</p>                      
            </div>
            <div class="col-xs-2 thumbnail">
                <a href="#" Title="Some website">
                    <img src="Spacer.png" alt="Some website">
                </a>
                <p>This is a title</p>                      
            </div>
        </div>
    </div> <!--end Portfolio-->