The recent heavy rains lashing the Houston area have given rise to an unusual and unsettling problem: the appearance of poisonous, foot-long hammerhead flatworms. These nocturnal creatures pose a significant threat as they regenerate when cut, making them difficult to eliminate.
Hammerhead flatworms: A toxic threat
The hammerhead flatworm, known for secreting toxins that can cause skin irritation in humans, thrives in hot tropical climates. This flatworm, which can become poisonous to pets if ingested, carries parasites and is often found on roads, sidewalks, and lawns after heavy rains flush them from their underground burrows.
Expert advice: Do not cut the worms
Experts warn residents against cutting these worms, as doing so will only lead to their regeneration. Ashley Morgan-Olvera from the Texas Invasive Species Institute told KHOU, “It will regenerate. So if you chop it into two pieces, you get two worms.” Instead, residents are advised to wear gloves, collect the worms in a plastic bag with salt and vinegar or citrus oil, and then freeze them overnight.
Handling hammerhead flatworms safely
Even after the worm is dead, experts caution against touching it. In case of contact, individuals should immediately rinse the affected area with water and soap, followed by using hand sanitizer. Also known as arrowhead or shovelhead worms due to their distinctive head shape resembling a hammerhead shark, these worms can grow nearly 15 inches long and are sometimes mistaken for snakes. Hammerhead worms prey on earthworms, which are vital for crops, gardens, and natural environments.
Asexual reproduction and regeneration
These flatworms can reproduce asexually, with a portion of the worm breaking off to grow a new head, resulting in a new flatworm genetically identical to its parent.
“A portion of the rear of the worm breaks off and grows a new head, producing a new flatworm genetically identical to its parent — a literal ‘chip off the old block,’” said Dr Layton. As Houston residents grapple with the dual challenges of heavy rains and the emergence of these toxic flatworms, it’s crucial to follow expert advice to manage this invasive species safely and effectively.