strange maybe-beetle found on ceiling

Hi! I live in Illinois. I saw a small black bug on my ceiling earlier today and when I went to grab it with a napkin it began to make a weird almost-clicking noise. It's hard to describe. It freaked me out so I plopped it in a cup with some apple cider vinegar because it was nearby. It's pretty small (pics are zoomed in quite a bit), and it appears to have some kind of white-ish spots on its back. Anyone have any clue what this thing is? 


i.imgur.com/GWNcg6E.png

i.imgur.com/LFTm04g.png