Poisonous hammerhead worms rising in Texas. When chopped in two, they double

A creepy-crawly invasive species known as the hammerhead worm is reappearing in Texas, following several weeks of excessive rainfall.

While hammerhead worms tend to stay out of the sunlight, hidden from plain sight, the extra rain has "flushed out" the wriggly creatures, Ashley Morgan-Olvera, Texas Invasive Species Institute director of research and education outreach, told USA TODAY.

The invasive species thrives in hot tropical climates, and as recent conditions bring damp, humid weather to the region, experts expect the invertebrate to emerge in full force.

What does a hammerhead worm look like?

Known for its head shaped like a hammerhead shark, the worm is typically light, honey-colored with a darker collar and one to five stripes on its body, according to the Texas Invasive Species Institute. The worm's narrow body can be up to 15 inches long.

Are hammerhead worms dangerous?

Aside from the frightening thoughts of approaching a footlong worm — or up to 15 inches in length — with a hammer-shaped head, the creature also secretes toxins that can cause skin irritation if touched. Additionally, they are known to carry parasites.

Morgan-Olvera told USA TODAY that they are not dangerous to household pets, and if a dog or cat eats one of the worms, they will likely get nauseous and throw it up, but there is no long-term threat. With their sticky bodies, hammerhead worms may get stuck to pet fur, but the worms will not irritate their skin, Morgan-Olvera added.

That said, they are bad for the environment as they prey on earthworms, which they paralyze with their slime before digestion. Earthworms are essential for organic matter decomposition and soil health in gardens, forests, prairies and farmland.

What to do if you see a hammerhead worm

As might be expected with a creature this creepy, eliminating the hammerhead worm isn't easy. They're actually regenerative, which means they can recover fully when chopped in half — and they will actually double in population.

"It will regenerate," Morgan-Olvera told KHOU last year. "So if you chop it into two pieces, you get two worms."

Instead, the expert recommended placing the worms in a plastic bag with salt and vinegar or citrus oil — and placing them in the freezer overnight. No one should handle the worm without proper protection, including gloves, even when dead.

If touched, officials recommend immediately rinsing the affected area with soap and water, followed by applying hand sanitizer.

Which states have hammerhead populations?

Native to Asia, the hammerhead worm is believed to have entered the U.S. through plant trade routes. They're predominantly invasive to the southeastern United States, with confirmed populations in Texas, Alabama, California, Florida, Georgia, Louisiana, Mississippi, North Carolina and South Carolina.