Watch CBS News

Invasive worm that can make pets sick prompts warning in Maine: "Don't squish or cut them"

Marine expert sees uptick in hammerhead shark sightings off Massachusetts
Marine expert sees uptick in hammerhead shark sightings off Massachusetts 01:05

A state agency in Maine is warning residents about an invasive species that can sicken your pet. The Department of Inland Fisheries & Wildlife posted last week about a "hammerhead worm" that's been sighted several times over the past few years.

The worms, also known as land planarians, earn their name from their heads that are reminiscent of a hammerhead shark. They are native to southeast Asia but have been in the U.S. since 1891, according to the U.S. Department of Agriculture

Hammerhead worms are mostly found in the Southeast but have been moving up the East Coast.

"If they become established in Maine, they may impact soil composition and native plant growth," the department said in a Facebook post.

This is a hammerhead worm. If you are thinking that it doesn't look like it belongs in Maine, you're right! But there...

Posted by Maine Department of Inland Fisheries & Wildlife on Wednesday, August 6, 2025

They can also make pets sick if ingested and irritate human skin, the agency added.

According to iNaturalist, a crowdsourcing website for sightings of plants and wildlife, hammerhead warms have been spotted from Portland to Bar Harbor in recent years. They've been documented even more frequently in Massachusetts and locations further south, the map shows. 

Anyone who finds a hammerhead worm should put in a bag and freeze it for up to 48 hours, experts say. They should throw them away in the trash instead of outside.

"Don't squish or cut them," the department said. "That's how they multiply!"  

People are encouraged to submit sightings to the iNaturalist website and contact the Maine Warden Service if they are spotted in plant soil sold at a store. 

View CBS News In
CBS News App Open
Chrome Safari Continue