<div class="navbar navbar-default" role="navigation">
<button class="navbar-toggler" data-toggle="collapse" data-target=".navbar-collapse">
    &#9776;
</button>
<div id="menuMieszkaniec-ajax" class="navbar-collapse collapse">
    <ul class="nav">
            <li>
                (...)
            </li>
            <li>
                (...)
            </li>
    </ul>
</div>
</div>