ONTARIO—The Invading Species Centre is indicating that although a lot of attention and concerns are being raised with the Land planaria, also called terrestrial flatworms or hammerhead worms, and the detrimental effects it can have on humans and small pets, this invasive species has been in Ontario for a long time and that the risks to humans or pets if they come in contact with them are overestimated.
The hammerhead flatworm “is a species that is getting a lot of attention these days,” said Morgan Daniels, an invading species hotline intern. “But in relation to this, the ministry (of Natural Resources and Forestry) is not concerned about it. We know that the hammerhead worm has been in Ontario for more than 14 years, so the recent sighting in St. Thomas, Ontario is not new.”
“We do have some concerns with it being sighted in Ontario, but despite the concerns being raised by some people that they produce a neurotoxin and there is potential harm to humans and animals, it is not extreme,” said Ms. Daniels. “The impact is not severe, and if a person has been in contact with this worm, if they wash their skin right after touching it there will be no impact. And if you have a pet or animal that has been in contact with this species of worm, just give them a bath and they will be fine.”
“We haven’t been tracking where they have been found due to the low risk they pose,” continued Ms. Daniels. “We know they are disbursed in Ontario and their impacts are not too worrisome. We would recommend if someone wishes to report seeing this species of worm, they can go onto the iNaturalist website to report this on the worldwide public information site.”
An online post last week from a person in southern Ontario explained the hammerhead flatworm was spotted in St. Thomas on April 15. The species is a worm-like animal that lives in moist, terrestrial environments. Species in North America are typically yellow or orange with dark stripes to dark brown or black. Hammerhead flatworms are an invasive species, meaning that they are not native to Ontario (like all earthworms).
Ms. Daniels said, “They should be treated like a slug. We don’t necessarily want them here, especially for those who have gardens, but they aren’t as much of a concern as some are indicating on the internet.”
