How to Get Rid of Invasive Hammerhead Worms

Hello, my friend, hello again; today we come together to talk about How to Get Rid of Invasive Hammerhead Worms and hope the blog can help you.

Your garden (and the earthworms inhabiting it) will thank you for destroying hammerhead worms, but you’ll need to take special measures to eradicate them safely. Pro tip: Don’t cut them up!

Thanks to the half-moon shape of their heads, hammerhead worms are known by many names, including hammerhead flatworm, arrowhead flatworm, and broadhead planarian (a category of flathead worms). Dubbed a “toxic terrestrial flatworm,” the hammerhead worm is a carnivorous land planarian known to prey on earthworms, slugs, insect larvae, and other hammerhead worms. Because they feed voraciously on earthworms, which are critical for their role in aerating and fertilizing soil, hammerhead worms are considered a threatening invasive species.

Native to Southeast Asia, hammerhead worms have been found in numerous parts of the United States since the early 1900s and have become invasive around the world. In fact, they’ve recently been spotted invading the D.C. area and New York state. However, their need for high humidity restricts them mostly to tropical and subtropical regions. They prefer cool, damp habitats, and because they are light-sensitive, they feed at night.

According to Michael Skvarla, Ph.D., assistant research professor of arthropod identification at Pennsylvania State University, “Bipalium adventitium has the widest range and occurs as far north as Ontario. Bipalium vagum is found primarily in the Southeast and only occurs in greenhouses and other protected structures in the Northeast, as they can’t survive outdoor winter temperatures.”

What do hammerhead worms look like?

Like the hammerhead shark, the hammerhead worm gets its moniker from its distinctive spade-shaped head. It has a long, flattened body that ranges from 8 to 15 inches, and it can be found in shades of gray, brown, gold, and green. The worm secretes a potent neurotoxin, tetrodotoxin, which it uses to immobilize its prey and deter predators. The noxious chemicals it releases can cause skin irritation in people and trigger nausea in animals who consume the worms, although that’s highly unlikely, according to Skvarla (more on this below).