ST. LOUIS COUNTY – St. Louis County Parks and Recreation has announced it recently received a report of an invasive hammerhead worm at Cliff Cave Park in St. Louis County, warning visitors that the flatworm can harm the local ecosystem and pose risks to people and pets.
The hammerhead worm, originally from Asia, preys on native earthworms, which are essential for healthy soil. Officials said the worms are usually seen after heavy rains and tend to hide under logs, rocks, and leaf litter.
Hammerhead worms are predatory land flatworms identified by their distinct half-moon or shovel-shaped heads. Native to tropical and subtropical regions of Asia, they are considered invasive in North America and Europe, where they pose a threat to beneficial earthworm populations.
St. Louis County Parks and Recreation officials said earthworms are vital to the ecosystem because they naturally fertilize soil, improve drainage, and can boost crop yields by up to 25 percent. The department said earthworms recycle nutrients and aerate the ground.
Officials also warned that hammerhead worms can regenerate, meaning cutting one into pieces can result in each piece becoming a new worm. The worms also release toxins that can irritate the skin and, if eaten, can make people and pets sick.
The department advised anyone who spots a hammerhead worm not to handle it with bare hands and to avoid cutting it.
To safely euthanize the worm, officials said people should wear gloves or use a shovel to place it in a sealed plastic bag.
Vinegar, rubbing alcohol, salt, or soapy water can be added to the bag, or the sealed bag can be placed in a freezer for 48 hours, according to the department. The sealed bag should then be thrown away in the trash.
