Don’t be alarmed if you see a foot-long slithering creature with a head shaped like a half moon pop up in your yard after a long rain.
This slippery fellow is not a snake, nor a monster from a science fiction novel. According to Garrett Hibbs, Hall County UGA cooperative extension agent, this invasive species is commonly known as the hammerhead worm, a native resident of Southeast Asia.
They’re often yellow or green in color with a few dark stripes running down their bodies and can grow up to a foot in length. Hibbs said like earthworms, hammerhead worms often migrate to the surface after wet weather events.
Over the past two weeks, Hibbs said he has received concerned calls about this strange-looking worm, most of which have posed the question: How do I get rid of them?
“They’re an invasive species, but what I like to remind people is that they’ve been here for around 100 years,” Hibbs siad. “There is really no chemical you can use to treat for them.”
Hibbs said people can raise their soil’s temperature through solarization -- a process that uses clear plastic to trap the sun’s heat -- to 93 degrees for five minutes to eradicate hammerhead worms. However, they run the risk of also eliminating earthworms, and the invasive species may choose to burrow farther into the ground, avoiding the hot temperature.
Hibbs said hammerhead worms have no known natural predators in Georgia, but are oddly cannibalistic.
“They go after each other, and I think that somehow has kept them in check,” he said.
Although he is unsure about the extent of hammerhead worms’ range in the U.S., Hibbs said he does know they are prevalent in Northeast Georgia. He said they hunt earthworms and slugs.
Unfortunately for earthworms, Hibbs said the invasive species is significantly faster, often following a trail left by their prey and catching up to them.
“They wrap them (earthworms) up, and they produce a mild dose of tetrodotoxin, a similar toxin to pufferfish,” he said. “They’ll stun them that way.”
So far, Hibbs said hammerhead worms haven’t negatively affected native species populations in Georgia, including earthworms. He assures people that the creature hasn’t been known to harm humans.
“Because they can get to a foot long, a lot of people will mistake them for a juvenile garden snake at first,” he said. “They’ve been here for a while. It’s no reason to be alarmed.”