Beware of the Toxic Invasive Hammerhead Worms Lurking in Your Backyard

Invasive hammerhead flatworms, known for their distinctive curved heads and toxic mucus, have been hiding in plain sight in the US for decades. These worms, which can secrete tetrodotoxin, a neurotoxin found in puffer fish and blue-ringed octopuses, are already widespread and abundant in New York state and likely more of the country than previously suspected. Climate change may be contributing to their northward expansion. While the worms can cause skin irritation in humans and sicken pets if eaten, their impact on ecosystems, particularly their predation on earthworms and endangered snails, is still unclear. Removing them is challenging, as slicing them up only leads to more worms. Caution should be used when handling them due to their toxic mucus.