If you see a hammerhead worm, remember: salt, don't slice!

SCOTT SIMON, HOST:

Michael Raupp is a bug guy.

MICHAEL RAUPP: I try to demystify the lives of invertebrates, particularly insects.

SIMON: He's professor emeritus in the Department of Etymology at the University of Maryland. For a bug guy, he's recently had a wormy time. Even his current Zoom background is a picture of a striped, slithery invertebrate with a shovel-shaped head - in other words, not BJ Leiderman, who writes our theme music. Professor Raupp describes this being as looking like a whole-wheat noodle.

RAUPP: This is Bipalium. This is a hammerhead worm, and that's its hammerhead right there. These are some of the creepiest creatures on the planet. These are, like, tiny nightmares in your landscape.

SIMON: Bipalium - Latin for two shovels - is a type of flatworm, a pretty disagreeable group of worms in the estimation of the professor.

RAUPP: Many of these are internal parasites of humans and other organisms. You know, I saw liver flukes in the slaughterhouses of New Jersey. We visited those in our pathology class. And I've seen tapeworms, you know, coming out of the rear end of a cat and things like that.

SIMON: Despite such vast experience, Professor Raupp had never seen a hammerhead until his friend, Washington Post reporter Kevin Ambrose, found one in his backyard - or more accurately, around Kevin Ambrose's little dog, Peanut.

RAUPP: Apparently, Peanut went out one morning when the hammerhead worms were moving from one part of the property to another part of the property across the driveway. Unfortunately, Peanut stepped on one of the hammerhead worms, and it became entangled on her leg.

SIMON: Ambrose emailed Raupp - hey, do you know anything about hammerhead worms? The bug guy grabbed his Tupperware and headed right over.

RAUPP: These hammerhead worms propel themselves across the surface of a lawn or a driveway with something called the creeping sole.

SIMON: That's S-O-L-E as in the bottom of a shoe.

RAUPP: The creeping sole is a series of small cilia, or hairs, on the undersurface of the worm that help it glide across the surface. Once they find their prey, they begin to secrete very vast amounts of sticky, sticky slime or mucus. This entangles their prey. Once the prey has become entangled, they will also secrete a very potent toxin called tetrodotoxin, which is the same toxin that's found in the puffer fish. This will paralyze the muscles of its prey.

SIMON: Don't worry - Peanut got a bath, and she's fine. What makes hammerhead worms especially unpleasant apart from the fact that their mouth is also their anus and if you cut them in half, they will regenerate? OK, OK. A lot of things make them unpleasant. But what's really alarming is that these worms are an invasive species.

ASHLEY MORGAN-OLVERA: What classifies something as invasive is, is it causing more harm than good?

SIMON: That's Ashley Morgan-Olvera, the research and education director for the Texas Invasive Species Institute. She says the hammerhead worm causes harm by eating local earthworms.

MORGAN-OLVERA: If you think about, you know, honeybees being vital in the chain reaction, on why we need to protect our honeybees, earthworms are necessary as well. So if we had a flatworm come in and if we left them unattended, if we just let them go and eat all the earthworms that they wanted, we could have serious crop and food issues.

SIMON: Morgan-Olvera says the hammerhead worm likely hitched a ride over to the U.S. in the early 1900s when they were accidentally imported with plants. Now they thrive from Pennsylvania to Hawaii. So what should you do if you come across a hammerhead? She says the neurotoxin isn't especially dangerous, but you ought to wash your hands if you touch the worm. And you should definitely dispose of the worm.

MORGAN-OLVERA: They are really sensitive to vinegar spray. So if you see them in your yard, you can just spray them with vinegar, and they will dissolve. You don't have to worry about touching them. But if you are removing them, it's important to just seal the container, whether it's a bag or a jar, just something to ensure that they're really getting disposed of.

SIMON: You can also salt them. Salt and vinegar, a vinaigrette in your garden. Ashley Morgan-Olvera of the Texas Invasive Species Institute says she understands why the hammerhead worm can seem a little grisly to people who don't get paid to look at them. But she says she's heartened by something hammerheads cannot do.

MORGAN-OLVERA: I would say I'd be more weirded out with roaches and things like that. There's something calming about something that can't fly, right? The hammerhead flatworm can't fly. So that's comforting.

SIMON: But she did tell us, there is such a thing as a jumping worm.

MORGAN-OLVERA: Superproblematic. That one's a problem.

SIMON: Wait. I think I just heard one. Oh. Transcript provided by NPR, Copyright NPR.