Large bat colony drives National Weather Service's radar batty

A large swarm is also called a "cauldron" of bats -- and this one caused some rather, um, stirring radar imagery.

Bonnie Burton profile photo
Bonnie Burton profile photo
Bonnie Burton
Journalist Bonnie Burton writes about movies, TV shows, comics, science and robots. She is the author of the books Live or Die: Survival Hacks, Wizarding World: Movie Magic Amazing Artifacts, The Star Wars Craft Book, Girls Against Girls, Draw Star Wars, Planets in Peril and more! E-mail Bonnie.
Bonnie Burton
2 min read

If you're this close to a Mexican free-tailed bat, you're probably too close. 

Video screenshot by Bonnie Burton/CNET

It's not Halloween yet, but that didn't stop a large bat colony from invading the National Weather Service's radar. A cauldron of bats -- the creative collective noun for a group of bats -- showed up in Phoenix, Arizona, on Sept. 13.

Meteorologists first thought the large bat swarm might be rain clouds. But it was soon revealed that those clouds were indeed Mexican free-tailed bats flying en masse. The NWS tweeted out an impressive animated GIF of the bat madness:

"That doesn't look like a normal shower, the way everything is sort of fanning out," National Weather Service meteorologist Sean Benedict told WSMV news. "They don't really have a uniform direction. That's usually your clue initially that it's probably animals flying around."

The radar most likely captured footage of the Mexican free-tail bats leaving a cave or a tunnel, then flying round to find bugs to eat across Phoenix. It's also not just one kind of bat that can be seen in the night skies of Phoenix either. It's estimated that 28 bat species can be found in Arizona.

The National Weather Service had some fun on Twitter on Sept. 14, asking followers what they thought the large mass on the radar could be. 

Bats often migrate to Arizona for the summer, and the Arizona Game and Fish Department has a few pointers on where the best spots are to watch bats do their thing if you want to check 'em out in person. 

"Each summer several thousand Mexican free-tailed bats and canyon bats use the Maricopa County Flood Control Tunnel, just west of the Phoenix Country Day School soccer fields near 40th Street and Camelback Road as a roost," according to the Arizona Game and Fish Department website

The department also reminds people that there's no reason to fear a bat emergence, though you probably shouldn't try to catch a bat or scoop one up. 

"Bats can fly all around you without making contact, thanks to their superior navigation abilities," says the website. "But no one should pick up a bat on the ground. Like any wild animal, bats will bite in self-defense. Bats pose little threat to people who do not handle them."