jquery closest() not working to get parent ul

jquery closest() not working to get parent ul

I have a handle the following element as this:

<ul class="blog-tags"> <li> demand <i class="fa fa-close"></i> </li> </ul> this.closest('li') 

returns a reference to the closest li element. but

this.closest('ul') 

returns null. I also tried

$(this).closest('ul') 

which also returns null. I also tried by class name:

$(this).closest('.blog-tags') 

but I'm still not getting a handle to the element. Any idea what might be wrong here?