City Cast DC logo

Giant Poisonous Worms Are Taking Over DC

Posted on July 27, 2023   |   Updated on September 30, 2025
Kaela Cote-Stemmermann

Kaela Cote-Stemmermann

The hammerhead flatworm / broadhead planarian (bipalium) is a predatory land planarian.

The hammerhead flatworm / broadhead planarian (bipalium) is a predatory land planarian. (samuel howell/Getty Images)




A killer worm that resembles a piece of cooked linguine is invading D.C. Nicknamed the hammerhead worm for its strange mushroom-like head, it can grow up to two feet long, can separate itself, and is highly poisonous.

The Bipalium worm is an invasive species and natural predator that hunts earthworms, snails, and slugs which can upset the forests' ecosystems. It secretes tetrodotoxin, a debilitating neurotoxin (also found in puffer fish) that can cause paralysis and even death.

Luckily for humans, the worm only causes skin irritation, but it can be deadly for pets. It can also break into multiple pieces, each functioning as its own worm that can regenerate into more sticky worms.

Bipalium worms were first spotted in the DMV 15 years ago, but recently sightings have increased. Residents in Oakton, Virginia are finding five to seven hammerhead worms in their yard per day.

Don’t touch! (samuel howell/Getty Images)

Don’t touch! (samuel howell/Getty Images)

Ecologists say don’t handle and definitely don’t eat the worms (not my first reaction, but just to be safe). Unfortunately, they can be hard to get rid of. The best thing to do is immobilize them with salt, use gloves to put them in a plastic bag, freeze them, and then trash them.

This is one of many invasive species that has been spotted in D.C in the last year like snakeheads, stink bugs, and spotted lantern flies to name a few. If you come across one, report it to your local county authorities or Department of Agriculture.

see more:health

Share article

Hey DC

Stay connected to City Cast DC and get ready to join the local conversation.

Can't subscribe? Turn off your ad blocker and try again.

Urban Almanac

See All
Urban AlmanacMarch 19

How To Start an Urban Garden In DC

Even in the city, you can grow your own food. Here’s how to make use of even the tiniest spaces, whether you’re designing your community...

Garden beds at Bruce Monroe Community Garden in Columbia Heights.
Urban AlmanacSeptember 4, 2025

How to Experience the 2025 National Book Festival in DC

This Saturday, Sept. 6, the Library of Congress is throwing a party for book lovers: the 25th annual National Book Festival.

The flyer for the National Book Festival.
Urban AlmanacJuly 30, 2025

How to Manage and Stop the Spread of Invasive Lanternflies

The invasive spotted lanternfly has returned to the Washington, D.C. region this summer. Here's what you need to know about why it spread...

A person holds an adult spotted lanternfly found in Huntington, Indiana, on Aug. 17, 2022.
Urban AlmanacJuly 31, 2024

Does Extreme Heat Cause Sudden Branch Drop Syndrome?

After the tragic death of a woman in D.C., local officials are investigating if extreme heat contributes to Sudden Branch Drop Syndrome.

After the tragic death of a woman in D.C., local officials are investigating if extreme heat contributes to Sudden Branch Drop Syndrome. (jiamiao lin/Getty Images)
Urban AlmanacJune 12, 2024

How To Forage in the DMV

An ancient foraging proverb says, “there are old foragers and there are bold foragers, but there are no old, bold foragers!”

Beautiful and edible chickweed. (mikroman6/Getty Images)
Urban AlmanacMay 8, 2024

Maryland Renames Snakehead Fish In Hopes of Increasing Demand

Maryland is renaming the invasive snakehead fish in hopes of getting more people to eat it. The snakehead fish will soon be known as the...

An invasive Northern snakehead caught in the tidal marshes of Southeast Virginia.
Urban AlmanacApril 17, 2024

How To Water Your Street Trees

One critical piece of this is to water your street trees, especially if you have a young tree outside your house or apartment.

A well established sidewalk tree.
Urban AlmanacApril 3, 2024

How To View The Solar Eclipse In DC

A solar eclipse occurs when the moon passes between the sun and Earth, blocking out our precious sunlight for a few rare minutes.

The sky during a full solar eclipse

The latest in DC

DC, Explained

How Adams Morgan Got Its Name

How community members gave Adams Morgan and a uniting cause.

A rooftop view of homes covered in snow.
Food & DrinkApril 15

DC's Best New Restaurants and Bars

Welcome to our rolling list of all the best new restaurants opening in Washington, DC!

Steak at Bazaar Meat by José Andrés. (Photo by Liz Clayman)
DC's BestApril 14

DC Blooms Better Than the Cherry Blossoms

The city is filled with flowering trees and bushes that get overlooked thanks to the spotlight-stealing cherries.

Gardens at Hillwood Estate. (Photographed by Erik Kvalsvik/ Courtesy Hillwood Estate, Museum & Gardens)
Local CivicsApril 13

Why the Holocaust Museum Self-Censored Before Trump Even Asked

The Holocaust Museum has been quietly changing its content since President Trump returned to office to avoid drawing the administration’s...

The United States Holocaust Memorial Museum. (ajay_suresh/Wikimedia Commons)
Food & DrinkApril 9

DC's Top Food Critic’s Favorite Spots

The food critic at the Washington Post has long been seen as an all-powerful — and totally anonymous — figure in the local restaurant ind...

Washington Post food critic Elazar Sontag. (Photo courtesy of Elazar Sontag)
Neighborhood GuidesApril 8

Get to Know 11th Street NW in Columbia Heights

11th Street in Columbia Heights is one of my favorite hangout spot in the District. You can garden, snack on crispy pig ears, and grab fr...

11th Street NW, Columbia Heights. (Google Maps)
DC, ExplainedApril 6

Inside the Story of Elon Musk’s Failed DC Hyperloop

Before Elon Musk's DOGE there was his fantastical hyperloop. But, it went down as one of the biggest transport flops in D.C. history. We...

President Donald Trump speaks during a news conference with Elon Musk. (The Washington Post/Getty Images)
DC, ExplainedApril 2

Mosh Madness: DC’s Next Big Music Festival Is Also a Basketball Tournament

Mosh Madness, D.C.’s premier music festival slash basketball tournament is back for its second iteration this spring. On April 11 the DMV...

Pretty Bitter rock as ballers try to block. (Photo by Bailey Payne)