A reference term for when you have a booger in your nose that is clearly visibly from the outside.
This context is found in an episode of Sex and The City.
When I was growing up: "Bats in the Cave" is when you spread a guy's shitter so you can buttfuck him but he's got a load of black dingleberries hangin' from his asshairs.
I was about to do damage to Pete's anus, but damn that dude had about a hundred hangers janglingin the wind: Bats in the Cave, dude. STANK.