Expert Reveals How to Identify and Combat Destructive and Invasive Hammerhead Flatworms 

Hammerhead flatworms are an invasive species that is a predator of earthworms. Crops, gardens, and forests depend on earthworms to survive, and hammerhead flatworms kill them.

Be warned: hammerhead flatworms are an invasive species that’s spreading across several states, including Texas, Florida, Georgia, and South Carolina

But what exactly are hammerhead flatworms?

“It looks exactly like it sounds,” Ashley Morgan-Olvera of the Texas Invasive Species Institute explains. “It is a flatworm with a hammerhead-shaped head. So if you think of a hammerhead shark, put that head on a worm, and that's exactly what it looks like.”

And she says in a lot of ways, hammerhead flatworms are more of a threat than their underwater counterparts.

“The hammerhead flatworm is an invasive species that is a predator of earthworms. And even though it's also a worm, people think what's the difference between them, and really it's that one eats the other. So, that's where we're more concerned about it.”

Regular earthworms are good for the soil. So the enemy of our friend is… our enemy.

“It causes ecological harm,” Ashley said.” It harms our environment by killing earthworms, which can cause money problems because our crops, our gardens, our forests, they depend on earthworms to survive.”

"They do not cycle soil to provide more nutrients,” she adds. “If anything, they're removing the nutrients from the soil by eliminating earthworms.”

As Ashley points out, flatworms are well-designed to be very, very annoying.

“It's flat, so that means that it can squeeze into places. It doesn't have a thick cuticle or skin like we see earthworms having. So it's really, really problematic because it can squeeze into anywhere. It can live where the earthworms live and feed off of them.”

They can also defend themselves in a way that is harmful to animals. They secrete chemicals that make animals like chickens, dogs, and cats sick to avoid getting eaten.

And if your dog eats a flatworm? It makes them sick, but they are not deadly.

“It just makes your dog throw up, and then the flatworm does survive afterward,” Ashley says. “I had vet clinics calling and reporting that yes, we had a dog, it was sick, and the flatworm was alive when the dog threw it up.”

Ashley described in detail how someone could spot a hammerhead flatworm.

“They can be anywhere from four inches to 18 inches long,” she explains. “They look like a snake, they're very long and skinny, and people will often mistake them for a baby snake. And then you see that hammerhead.”

“And so they can have striping on them or even like a collar around their neck, if you will. So they're pretty obvious when you see the head.”

Ashley adds that, unfortunately, anyone who has hammerhead flatworms has to be careful about getting rid of them.

“You definitely don't cut it up. Don't cut it into pieces,” she explains. “That tends to be a lot of people's reactions, but being a flatworm, that means it can grow. It doesn't need a mate to reproduce. So if you cut it into pieces, it'll become more flatworms in just a couple of days.”

“You can squish it if you want to. I think that's a little gross, but as long as you're getting the whole flat warm, you got to make sure you get the whole flatworm.”

So what should you do if you see this worm? Ashley has a great solution.

“I recommend putting it in a container. It could be a resealable container that you can put as many flatworms as you want. It could be a Ziploc bag with just a little bit of salt, but you put that whole flatworm in there.”

Afterward, it’s best to seal it and throw it away.

“That way, it's euthanizing. The flatworm is gone,” Ashley says. “It can't crawl out because remember they can squeeze out of really small places. So if you just throw it out, it'll climb out. It'll go on and live about its life. So this way, you're ensuring it is not going anywhere and it can't eat any more earthworms.”

And only humans can get rid of hammerhead flatworms.

“It really does come down to anybody, any human, finding it and removing it from the environment because we think that they traveled in potted plants and importing and exporting of plants,” Ashley lastly states.

“So since we've helped them spread, it's up to us to remove them now. If we just do nothing, they're just going to stay there and multiply and eat earthworms.”

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