The first year we had them in the house, I couldn't sleep. They are clumsy flyers (OK, better flyers than I am!) who sound very loud, like a big angry wasp, and then they whack into something and fall down, often on their backs, and start clicking. Then they stop clicking...then they fly again, banging into the light fixture overhead, or a lampshade or books on the bookshelf, and then you hear the scrabbling of tiny hard beetle legs, and then the sound of them falling and hitting something else, and then...click...click....click....click..
Now...I manage to sleep, but if I'm up too late, they're already making noise when I go to bed and it takes longer. Last night one BUZZZZZZZZed across the room right after I'd turned off the bedside light, thwacked into the head of the bed, and I heard the little plop on the pillows. Turned light back on, found the intruder, and that one bit the dust with the help of a book. It was not, of course, the only one, but the next BUZZZZZZer hit the wall across the room and started clicking from behind something. I went to sleep.