comscore Horsehair worms likely culprit in swirling toilet-bowl mystery | Honolulu Star-Advertiser
Kokua Line

Horsehair worms likely culprit in swirling toilet-bowl mystery


Question: Recently we’ve noticed red/pink worms in the bowl of our toilet. They are very thin and approximately 1 to 2 inches long. Our concern is that this might be a parasite infecting one of our family members, but since we don’t see it anywhere else, we’re not sure whether it is just a pest or bug larvae. Do you have any ideas of whom we could contact?

Answer: We suggested you contact David Preston, an entomologist in the Natural Sciences department at the Bishop Museum, who identified the threadlike toilet invaders as apparent horsehair worms, also known as gordian worms.

Preston tempered his assessment, saying it was based on fuzzy photos, and said he could give a more definitive ID if you brought in an actual worm.

However, based on your description and the photos, he said they appeared to be horsehair worms, which are parasites of crickets, grasshoppers, roaches and other insects but harmless to people and pets.

An insect, probably a roach, got into the toilet bowl, he said.

At that point, “these worms immediately sense this and leave the roach’s body, thinking they are in a wet environment needed for the worms to lay eggs,” Preston explained. “This is why they are alive in the bowl.”

He said this is not a common occurrence, but is a well-documented one.

“The roach either escaped or went down the toilet, leaving behind the worms,” he said.

Horsehair worms vary in color, but white, brown and a reddish color are common. Preston also said they can be long, although length can vary.

Question: Every day I drive from Ala Moana Center, go down Keeaumoku Street and turn left at South Beretania Street. Turning left on South Beretania is the longest part of the journey, as the left-turn light does not seem to be long enough. It will only allow about half the cars, if that, to go through. I find myself waiting for at least two light cycles each day. Who is the person or what department can I contact with concerns about traffic light timing?

Answer: The easiest way to contact a city agency, such as the Department of Transportation Services, is on the city’s website:

Your complaint or concern is then forwarded to the proper agency. You can also contact certain agencies directly, for issues involved abandoned vehicles, refuse collection, bus operations, etc.

You can also email, call 768-4381 or write to Director of Customer Services, Mission Memorial Building, 550 S. King St., Honolulu 96813.


To Molly McDermott of CatFriends for helping me spay and neuter some feral cats, which I unwillingly inherited but felt responsible for. This organization will, for a small fee, spay and neuter the cats and microchip them so they have a second chance in life. Molly brought over traps and helped me catch the cats, took them to be spayed and neutered, and brought them back the next day. She took the time to look at the kittens and noticed a problem with one. She gave medicine and advice and answered all my questions and concerns. Anyone interested in the cause of keeping our cat population down, please visit their website,

— A.H.

The nonprofit CatFriends describes itself as an “all volunteer organization that is Oahu’s source of information and education for abandoned and feral cat issues. CF is the island’s leader in the humane control of abandoned and feral cats.”

Write to “Kokua Line” at Honolulu Star-Advertiser, 7 Waterfront Plaza, Suite 210, 500 Ala Moana Blvd., Honolulu 96813; call 529-4773; fax 529-4750; or email
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