Louisiana’s Toxic Hammerhead Worm – What to Know

LOUISIANA - A few years ago I came across a hammerhead worm here at the station and it stopped me in my tracks. This was the first time I had ever seen one of these worms and honestly, I thought it might be an alien.

Eventually I learned this worm was in fact not and alien, but a hammerhead worm. I was relieved because, it's just a worm. An odd looking worm but hey, I'm not here to judge. But also, a worm can't be dangerous right?

Well, it's a good thing I chose not to pick it up because hammerhead worms carry some toxic baggage along with them, as well as being oddly hard to kill, if you would need to that.

Come to think of it, the hammerhead worm kind of sounds like an alien.

From Lafayette to Opelousas, St. Martinville to Morse, you're about to start to seeing more and more hammerhead worms crawling around Acadiana, and here's what you need to know...

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What Are Hammerhead Worms?

Hammerhead worms are a type of land flatworm from the genus Bipalium. Their most recognizable feature is the wide, flattened head that looks like a shovel or hammer, pretty similar to a hammerhead shark.

They thrive in warm, damp environments, which makes Louisiana the perfect place for them to live and spread. You’ll most often see them after a good rain, especially in gardens, flower beds, or under mulch and debris.

Are Hammerhead Worms Dangerous?

Hammerhead worms move pretty slowly, thankfully, but don’t underestimate them. They pack a serious punch in a few different ways.

They Contain a Powerful Toxin
Hammerhead worms produce Tetrodotoxin, a potent neurotoxin also found in pufferfish. Touching them can irritate your skin, they make pets pretty sick if eaten, and the hammerhead's toxin can affect the nervous system.

While they’re not likely to cause severe harm to humans through casual contact, it’s still smart to avoid picking them up with your bare hands.

They Destroy Earthworms

Hammerhead worms are considered invasive for a few reasons, with one of the biggest reasons being their appetite for earthworms. They actively hunt and eat earthworms which causes big problems with soil quality which is really bad for plants, gardens, and grass.

They Can Regenerate If Cut

Like something out of an alien movie, hammerhead worms have the ability to regenerate if you chop one in-half. In some cases, cutting one worm can actually result in multiple worms forming from the pieces. That makes them especially difficult to eliminate if handled incorrectly.

How To Get Rid Of Hammerhead Worms Safely

If you come across one, don’t touch it with your bare hands. Instead, wear gloves or use a tool to pick it up, pour salt, vinegar, or citrus oil directly to the hammerhead worm, then place it inside of a sealed bag before throwing it away.

If you crush or cut one, you could make the problem worse.

You can learn more about the hammerhead worm at invasivespeciesinfo.gov.