I dunno about bats (since I’ve never seen any in Southern California, but maybe they just elude me), but I’ve seen a pair of crows do that. Burbank has a lot of 'em, and it’s pretty common to see them hanging around the Warner Bros studio lot. On the 4th floor of one of the parking garages, right next to where the 5th floor ends so there’s an extra-high ceiling, a pair of crows would spend every night roosting on one particular fire-sprinkler bar. The parking space below is still covered with their droppings. They were there every night for, like, years until a few months ago. Dunno why they split.
“Porch Ceded To Bats” is one of my favorite Onion headlines, along with the immortal “Owls Are Assholes.”
