A turd whirler is a pocket of air(fart) that travels down your poop shoot while whirling around the piece of poop you got in there. While it whirls and swirls about trying to get out, it captures the funky fresh aroma of the turd and then exits; letting you know you should probably go take care of that!
"Eww that stinks dude! It must be a turd whirler!"