Heavy Houston Rains Bring Out Toxic Invasive Worms That Multiply When Cut in Half

Their growing presence came amid a series of wet weather events, including historic river flooding in May and Hurricane Beryl in July

Houston residents are bracing for invasive and toxic hammerhead flatworms after an onslaught of heavy rain.

The flatworms, which are not only poisonous to both humans and pets, also multiply when cut in half, making them harder to get rid of than most slugs, according to CBS affiliate KHOU 11

Their growing presence came amid a series of wet weather events, including historic river flooding in May and Hurricane Beryl in July, Fox affiliate KRIV reported.

Texas continues to face downpours and thunderstorms that cause rivers and streams to overflow, turning even some yards into lakes, per KRIV. This could cause more people to spot the flatworms.

Hammerhead flatworms thrive in hot and humid climates and are often found “in soil, driveways, patios, and sidewalks, especially after heavy rains,” KHOU reported, and “can grow up to a foot long and emit a toxin” if they are picked up by humans or eaten by pets. 

The worms can cause a rash on your hands but can be far more dangerous to pets if they eat them, ABC affiliate WBMA reported.

Representatives from the City of Houston did not immediately respond to PEOPLE’s request for comment.

The poisonous worms, which are native to Asia, have been reported in Alabama, California, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina and Texas, according to the New York Post.

Dr. Blake Layton, an entomology expert at Mississippi State University, said in a 2019 report that hammerhead flatworms “are predators of earthworms and slugs which they track down, disable by covering them with slime, and consume by everting their ‘mouth’ over part of the earthworm’s body and digesting it.”

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories.

According to the Texas Invasive Species Institute, the flatworms can be killed with orange essence and salt and sprayed with vinegar or a combination of vinegar and citrus oil.

"Placing them in a Ziploc bag with salt or vinegar ensures the flatworm does not crawl away after treatment; then dispose of the sealed bag," the institute added. "Continuous removal of these invasive flatworms is necessary for the protection of naturalized earthworm populations."

The agency noted it is important to use gloves, paper towels and even a stick when handling the flatworms. They added, "Hands should be washed in warm soapy water, and rinsed in alcohol or a standard hand disinfectant."

Related Articles