City Cast DC logo
Advertisement image

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

Get smart about D.C. with our news roundup and analysis.

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

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