Harmful and invasive hammerhead worms get into Ontario
The hammerhead worm is a new invasive species that people in Ontario who like to garden and be outside need to be careful of. These flatworms, which look strange, are from Southeast Asia and have been living in the province since 2019. Sightings in Newmarket, Hamilton, and the Kitchener area in the past few weeks show that their populations are growing. [1]
The name "hammerhead worm" comes from the shape of their head, which is like a crescent moon. They can get up to 3 feet long and release tetrodotoxin, which is a poison that is very dangerous. This is the same toxin that pufferfish have. [2] This toxin is not usually deadly to people, but it can irritate the skin and make you sick if you eat it. However, it is a bigger problem for pets and small animals. [3]
Worms are thought to have come to Ontario by chance through nursery stock that was brought in from the US. [1:1] Because they eat native earthworms, hammerhead worms can change the soil's makeup and upset local ecosystems. [4] Because they can grow back from cut pieces, communities can spread quickly once they're established. [2:1]
To get the best view of a hammerhead worm, stay away from it. To move it, don't touch it with bare hands; instead, wear gloves or a tool. Find them? Tell the Invasive Species Center about it or record it on iNaturalist to help track their spread. [5] If a person or animal eats a hammerhead worm, they should get emergency medical help right away.
As these harmful invaders move across Ontario, it's important for people to stay aware and watchful. We can help hammerhead worms have less of an effect on our natural ecosystems by keeping an eye out for them and telling others when we see them. When you're in the yard next, keep an eye out for these strange new kids!
CTV News Toronto. (2024, April 27). Invasive and toxic hammerhead worms make themselves at home in Ontario. ↩︎ ↩︎
CBC News. (2024, April 17). Toxic hammerhead worm spotted in St. Thomas garden. ↩︎ ↩︎
Toronto Sun. (2024, April 27). 'They're here': Dangerous worms now wriggling in Ontario soil. ↩︎
CityNews. (2024, April 25). Invasive and toxic hammerhead worm is popping up in Ontario, GTA. What you need to know. ↩︎
Invasive Species Centre. (2024, April 27). Cited in CTV News Toronto article. ↩︎