Aliens with farm animal fetishes, Elvis still walking the earth, and "Bat Boy," a human hybrid who exited a West Virginia cave to conduct a nationwide reign of terror, were longtime staples of checkout-lane tabloids.

Before smartphones, perusing these fantastical cover stories was an amusing way to wait for the cashier to ring things up. Generally, few readers took these accounts seriously.

We don't recall any warnings about Bat Boy's perilous perambulations, for example, from friends, family or elected officials. The information's origin was clear and the Weekly World News and its ilk tended to trigger a "this is not a credible news source" filter.

Unfortunately, the collective mental muscle once powering that healthy skepticism has grown flabby as social media has replaced tabloids in fueling urban myths. Case in point: the ludicrous rumor that schools now have litter boxes for children identifying as cats.

Multiple reputable organizations including Reuters News Service, USA Today, NBC News and Snopes.com have tried to drive a stake into this evidence-free rumor. For the record, the Star Tribune Editorial Board also checked with Minnesota school administrators and some of the state's largest districts and found no evidence that litter boxes serve as alternative restrooms.

And yet this information zombie continues to defy death here and elsewhere, as recent Minnesota events regrettably illustrate.

This fall, Republican gubernatorial candidate Scott Jensen warned about school litter boxes at a political appearance. Earlier this year, three Minnesota GOP House members — Reps. Steve Drazkowski, Eric Lucero and Tim Miller — also sounded the false alarm.

Policymakers elsewhere have swallowed this tale, but Minnesota's embrace stands out. Comedian John Oliver poked fun at the state on a recent show and said, rightly, that "If you think about it for literally two seconds, the whole thing falls apart. For one, if kids were using a litter box in class, a state representative from Minnesota would not be the one breaking that news to you."

To Oliver's point, if this really happened, it would be news across the state and likely the nation within hours. Most school kids have smartphones. There's no way this would stay under wraps.

NBC News' disinformation reporting team deserves credit for its stellar debunking. In an Oct. 14 story, it followed up with politicians who spread this rumor. The reporters came away empty-handed when asking for evidence.

The team also uncovered a grim grain of truth that may have inspired this wild claim. The Colorado school district in which the Columbine High School is located "has been stocking classrooms with small amounts of cat litter since 2017." It's part of the emergency supplies kept on hand if there's a shooting and students are locked inside without restroom access.

It's disturbing that one school district's heartbreaking preparation could have metastasized into the belief that schools are encouraging kids to use a litter box. Why hasn't common sense kicked in?

Seeking answers, an editorial writer reached out to Michael Shermer. He gave a TED talk titled "Why People Believe Weird Things." He's also got a timely book coming out next week called "Conspiracy: Why the Rational Believe the Irrational."

Shermer notes that urban myths predate social media, citing rumors swirling in the 1970s about alligators in big-city sewers. Among the things that have changed is that there's now a phenomenon that he calls "tribal conspiracism."

Essentially, people may be more inclined to believe the far-fetched if those who share their political beliefs are pushing the disinformation. If you believe the other side is immoral or evil, you're already primed to accept assertions of dubious behavior. "Before you know it, you've got the kitty litter situation," Shermer said.

The Jan. 6, 2021, assault on the U.S. Capitol shows the harm of letting online rumors, in this case about the election, spread unchecked. Broader educational initiatives are clearly necessary to help students become savvier lifelong information consumers.

But foremost, individual responsibility is in order. Everyone can now be a publisher with a few clicks. Collectively, we have to do better at sifting out what's credible from what's not, with policymakers especially needing to shoulder this basic responsibility.

If something sounds like it might join Bat Boy on the Weekly World News' cover, step back and take a closer look before sharing it. It's not too much to ask.