A Reddit user in Louisiana turned to the platform after spotting an extremely long, flat, striped worm near their patio — and what began as a simple identification question quickly became a warning about invasive flatworms.

The unusual sighting, shared in the r/Vermiculture subreddit, raised concerns that the animal might be a hammerhead worm, an invasive predator known to threaten beneficial soil life.

At first, the poster wasn't sure what they were looking at.

"I looked closer today and don't see a hammerhead," they wrote, later adding that the head appeared to have "eyes" and "looks almost like a snake head, but it definitely has the body of a flat worm."

Commenters quickly offered possible identifications. One user suggested it could be Dolichoplana striata, while others said it still seemed likely to be a hammerhead-type flatworm despite the lack of the species' signature head shape.

The poster later said image search results for Dolichoplana striata appeared to match what they had found. Worried about the healthy worms already living in their yard and compost bin, they decided to destroy the flatworms.

Invasive flatworms can prey on earthworms and other soil organisms that play important roles in keeping gardens productive, improving soil structure, and helping organic matter break down efficiently.

A yard full of healthy worms often supports better drainage, stronger plant growth, and more effective composting. An invasive predator can upset that balance in raised beds, gardens, and backyard compost bins.

"My yard has a ton of healthy worms, I don't need anything messing with them," they wrote. The OP later added: "We would shovel one scoop of dirt and have a ton of earthworms there."

Commenters warned them not to cut the worm up.

Several users said that some invasive flatworms can regenerate from fragments, meaning that attempting to kill one by chopping it apart could make the problem worse.

Other commenters recommended placing the animals in salt or alcohol instead of crushing them, and the poster said they had used salt on the worms they found.

"DO NOT cut it up. These suckers can regenerate from a ridiculously small piece," one person wrote.

Another commenter added: "Try not to smash it with your shoe because of the toxin."

For this Louisiana family, the strange backyard discovery has already turned into a household alert system.

"My kids are now the best alarm system," the poster wrote. "MAMA I SEE ANOTHER ONE."

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