“I have found a hammerhead worm in my South Carolina landscape. What do I do?”
North Carolina State Extension wrote an excellent publication on terrestrial flatworms, with common species around yards and gardens in the Carolinas called land planarians or hammerhead worms: https://content.ces.ncsu.edu/terrestrial-flatwormshammerhead-worms.
Hammerhead worms are not native to our landscape but have been in our area for about 70 years.
Clemson Extension does not recommend management as it is not economically or ecologically feasible to eradicate hammerhead worms. Additionally, this particular organism acts as a biological control agent for potentially pestiferous critters such as snails, slugs, and other soft-bodied organisms.
If encountered, do not cut up hammerhead worms. Instead, according to the above-referenced North Carolina State Extension publication, “If the worm(s) can be picked up with tweezers or gloved hands, they can be killed in rubbing alcohol or put in a bag and frozen. To avoid direct contact, salt can also be used to effectively eliminate individual flatworms that are encountered around the home. If applying salt near plants, try to limit the amount applied as salt can harm vegetation.”
At the time of this writing, Clemson University’s Regulatory Services (https://www.clemson.edu/public/regulatory/) has had no response regarding control, quarantine, or eradication when hammerhead worm is found in South Carolina.
Clemson University’s Regulatory Services does not require hammerhead worm observations to be reported or documented when they are found in South Carolina. However, you are encouraged to add your observation(s) to iNaturalist (https://www.inaturalist.org/) and EDDMaps (https://www.eddmaps.org/), as these applications are two of the ways this organism is being tracked at this time.