HOUSTON — With all the rain we’ve had and are expecting across the Houston area, there’s a poison in the ground you should know about -- the invasive hammerhead flatworm.
These slugs can grow up to a foot long and can emit a toxin if you pick them up. And that can irritate your skin. The toxin could also make your pets sick if they try to eat one of them. They prefer hot and humid climates, which makes Houston the perfect spot for them to live. They're found in soil, driveways, patios and sidewalks, especially after heavy rains.
The rain we're going to see this week will flush the worms out of their burrows in the ground, putting you, your kids and your pets at risk.
But you can also use this rain to your advantage.
Morgan Young with our sister station, WFAA, reported on the worms, saying if you find them, put on some gloves, put them in a plastic bag with salt and vinegar or citrus oil and throw them in the freezer overnight. One thing you don’t want to do is cut it into pieces.
“It will regenerate,” said Ashley Morgan-Olvera, M.S., with the Texas Invasive Species Institute. “So if you chop it into two pieces, you get two worms.”
Don’t touch it even after it’s dead. Immediately wash your hands with soapy water and rinse them in alcohol or a hand disinfectant.
If you find a hammerhead flatworm, Morgan-Olvera told us in a previous story to send a photo and the address where it was found to invasives@shsu.edu. That way the department can track the data.
What are hammerhead worms?
The weird worms get their name from the shape of their heads and are also called shovelheads or arrowheads.
The Texas Invasive Species Institute says hammerheads are predators of the kindler, gentler earthworms that are necessary for the survival of forests, crops and gardens.
They track them down, disable them by covering them with slime and eat them by stretching their “mouth” over part of the earthworm’s body and digesting it, according to Dr. Blake Layton Jr., an entomology expert with Mississippi State University.
The same toxins they use to paralyze the earthworm are what can cause skin irritation in people or make animals sick.
Hammerheads also have the potential to carry parasites.
Not only do they regenerate if you cut them up, but something similar happens when they reproduce asexually.
“A portion of the rear of the worm breaks off and grows a new head, producing a new flatworm genetically identical to its parent, a literal ‘chip off the old block,’” Dr. Layton explained.
Like little vampires, they avoid the sun and prefer to hide in dark, secluded areas. They’re mostly active at night but might also slither out on cloudy days, Dr. Layton explained.
