Horsehair Worm in Toilet: What to Do – Quick and Effective Solutions for Homeowners

Discovering a horsehair worm in your toilet can be an unsettling experience. These long, thin creatures can measure from several inches to over 14 inches, with a width of 1/25 to 1/16 inch, and come in various colors ranging from whitish to brown/black source. Although not dangerous to humans, it’s natural to want them out of your toilet.

These worms are usually found near water sources, developing as larvae inside insects before emerging in water to complete their life cycle source. Despite their somewhat alarming appearance, they do not pose any harm to humans or pets.

So, what can you do if you find a horsehair worm in your toilet? Don’t panic! In the following sections, we will discuss practical steps to remove the worm and prevent future encounters.

Identifying Horsehair Worms

Horsehair Worm Characteristics

Horsehair worms are very long parasites of insects, typically found in moist places. They can measure from several inches to over 14 inches in length, and are quite thin (1/25 inch to 1/16 inch wide) ¹. Their color ranges from whitish to yellow/tan or brown/black¹. These worms usually knot themselves into a loose, ball-like shape, resembling a “gordian knot”²:

• Very long and slender
• Uniform in diameter
• Whitish, yellow/tan, or brown/black color
• Loose, ball-like shape when knotted

Organic Matter and Larvae

Horsehair worms are found on the ground or on plants, especially near water¹. They tend to appear around organic matter and typically parasitize various insect species³. In certain cases, they might be found in livestock water troughs and sanitation systems, including toilets³.

When dealing with horsehair worms, it is essential to remember that they do not harm people, pets, or plants⁴. Ensuring routine maintenance and cleaning of water supplies will help to prevent horsehair worms from occupying these spaces³.

Why Horsehair Worms Are in Your Toilet

Stagnant Water and Breeding Ground

Horsehair worms thrive in stagnant water, especially near plants. Toilets can inadvertently provide these conditions if not flushed regularly. For example:

• Unused guest bathrooms
• Infrequently cleaned toilets

Stagnant water in toilets can lead to a buildup of organic matter, creating a breeding ground for horsehair worms.

Cracked Sewer Pipes and Plumbing Issues

Another reason horsehair worms might appear in your toilet is due to cracked sewer pipes or other plumbing issues. Worms can use these cracks to enter the plumbing system. Some possible plumbing issues include:

• Damaged toilet seals
• Improperly installed plumbing

Here’s a comparison table highlighting differences between stagnant water and cracked sewer pipes:

Some features of horsehair worms in your toilet are:

• Long, thin, and uniform in diameter
• Range from whitish to brown/black in color
• Can measure up to 14 inches

Lastly, here are some pros and cons of horsehair worms:

Pros

• May help in controlling pest insects

Cons

• Can be a sign of plumbing issues
• May cause concern or discomfort for homeowners

Are Horsehair Worms Dangerous

Harmless to Pets and Humans

Horsehair worms are harmless to humans, pets, and plants. They are parasites of insects and commonly found in moist places. While they can be found in toilets, they do not pose a threat to your health.

Human Parasite and Household Pests

Horsehair worms mainly parasitize insects, particularly grasshoppers, and are not known to be parasites of humans or household pests. They have a minimal effect on natural invertebrate populations, and controlling them in natural water sources is not practical, as they may even have beneficial effects by parasitizing pest insects.

Bloodworms, Earthworms, and Nematodes

Comparing horsehair worms to other worms like bloodworms, earthworms, and nematodes:

• Horsehair worms and bloodworms are not harmful to humans, pets, or plants.
• Earthworms provide numerous benefits to soil health.
• Nematodes can be either beneficial or harmful, depending on the species.

In conclusion, horsehair worms are not dangerous to humans or pets. They are found in moist environments and parasitize insects like grasshoppers but not humans or household pests. Compared to other worms like bloodworms, earthworms, and nematodes, they are beneficial and pose no threat.

Removing and Preventing Horsehair Worms

Clean Your Toilet Thoroughly

To remove horsehair worms from your toilet, start by flushing the toilet to wash away the worms. Then, use a toilet cleaner to scrub the bowl, removing any remaining worms and their potential breeding ground. For best results, clean the toilet regularly to prevent reinfestation.

Example: an effective cleaner for removing worms and gunk includes products containing bleach or other strong disinfectants.

Drain Cleaning and Vinegar and Baking Soda Solution

Drain fly larvae are a common worm-like pest found in toilets, so it’s essential to clean your drains as well. Use a vinegar and baking soda solution to eliminate drain flies and their larvae:

1. Pour 1/2 cup of baking soda into the drain
2. Follow with 1 cup of vinegar
3. Let the mixture sit for 15-20 minutes
4. Flush the drain with hot water

Additionally, you can use enzyme-based drain cleaner products to dissolve the slime and gunk in the pipes that attract pests.

Eliminate Crickets, Cockroaches, and Other Insects

Horsehair worms commonly parasitize insects like cockroaches, crickets, and beetles. To prevent these worms in your toilet, you should eliminate their host insects:

• Seal cracks and gaps in walls, windows, and doors
• Keep your home clean and free of food debris
• Use insecticides or traps to control pests when necessary

Keep the Toilet Area Dry

Worms and insects thrive in damp, moist environments. To prevent worms in your toilet, try to keep the toilet area dry:

• Wipe down surfaces regularly
• Check for and fix any leaks around the toilet
• Ensure adequate ventilation in the bathroom

Features of a worm-free toilet:

• Regularly cleaned bowl and drains
• No visible insects or worms
• Dry and well-ventilated environment

Characteristics of an infested toilet:

• Presence of horsehair worms, drain fly larvae, or centipedes
• Damp, moist environment
• Attracts cockroaches, crickets, or other insects

Monitor Your Home and Garden

Plumbing System Maintenance

Regularly inspect and maintain your home’s plumbing. Fix any leaks and routinely clean sinks, drains, and toilets to prevent buildup of organic material, which can attract insects like cockroaches and millipedes.

• Pros:

  • Reduced risk of insect infestation
  • Better sanitation

• Cons:

  • Requires time and effort

Landscape and Puddle Maintenance

Keep your outdoor environment clean by removing any standing water or puddles. These can be breeding grounds for insects like dragonflies and can also attract horsehair worms.

• Pros:
  • Minimized insect breeding sites
  • Lower chance of horsehair worm infestation
• Cons:
  • Requires regular inspection of the yard

Neighboring Swimming Pools and Plants

Work with your neighbors to maintain clean swimming pools and healthy plants. Encourage them to eliminate any potential breeding sites for worms and insects such as crickets, which can serve as hosts for horsehair worms.

Examples of measures to take:

• Cover pools when not in use
• Frequently change the water in troughs and bird baths
• Trim overgrown plants and keep the area free of leaves and debris

Comparison Table

By following these practices, you can reduce the likelihood of encountering horsehair worms in your toilet and maintain a cleaner home and garden.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Flotsam from Oregon: Blood Worm in genus Glycera perhaps

Cannon Beach Ghost Millipede of the Sea?
February 4, 2010
On Sunday, January 31 at about 7:30 in the morning, my friend and I were taking one last stroll along the beautiful shore on Cannon Beach. The beach goes along south until it runs into some black rocks and tide pools. I’ve seen a lot of interesting things there, but this takes the cake.
Washed up on the sand, not caught in a tidepool but instead in a very shallow seabound stream, was a pale ghost of a creature that I admit, freaked me out. I’m pretty sure it was either dead or unaccustomed to surface pressure… it seemed quite limp in either case.
It was off-white, with an almost luminescent-looking greenish tinge. You can sort of see the color in the photo. And I couldn’t discern any eyes, just that rather spectacular pointed oblong of a head. And the spinal column… not that bugs necessarily have spines, but you know… was translucent, not whitish. You can see it in the photo; the translucent part seems to surround the …brain? Brrrr. Wow. Somewhere between 4 and 6 inches of fascinating, nameless wriggle – hard to say for sure with it folded up like that and me afraid to touch it (even with a stick).
I wish I had a better photo for you; the water was washing it back out to the ocean, and my camera is old and beat up. It certainly isn’t pretty enough to make picture of the month. But with any luck, you can tell me what this bizarre encounter was. Have you ever seen anything like it?
I haven’t, save perhaps in unremembered dreams…
Nikki Burns, still a Goonie
Cannon Beach, OR

Dear Nikki,
Your letter is wonderful, and this creature is a bit out of our typical request realm, though we have identified marine worms in the past.  We are posting it immediately as unidentified in the hopes that one of our readers will have some clue as to its identity, and we will begin to research ourselves.  Meanwhile, hold tight and we will see what we are able to uncover.  We would strongly suggest that you post a comment to your own letter in the event that sometime far in the future, an identification is provided.  We generally write back if we get an identification in a few days, but eventually, a querant’s email address vanishes into the black hole that our email account becomes after about a week.

Hi again Nikki,
On a lark, we just did a search for sea worm, and found the Wikipedia page on the genus Glycera, Blood Worms, and it sure looks like your critter.

Letter 2 – Dream of a Worm

description of worm, have dreams of them
January 7, 2011 10:23 pm
I keep having this same dream over and over.  In it there is a worm with either a red or orange head, four white segments behind, and on the first and last white segments, there are two black legs.  They come burrowing out of the person’s body, and they come out singly, but there is a lot of them.  What could these worms be?
Signature: Daniel

Dear Daniel,
WE are not in the business of dream interpretation, but we do have enough knowledge to know that dreams are a combination of many real life experiences and sensory data that are modified by psychological impulses including fears and desires.  Perhaps you have a fear of parasites.  There are numerous worms that can be found inside humans, including Tapeworms.  There are also some internal parasites that are insects like the Human Bot Fly.  There are also many somewhat wormlike insects with red heads that we have in our archives including the Tetrio Sphinx Caterpillar, a Walkingstick from Ecuador, the Red Headed Centipede, the Red Headed Pine Sawfly Larva and the Azalea Caterpillar.  We cannot say for certain that your dream worm does not exist, but since you are unable to send us an image of what is going on inside your head, we are going to have to leave it as unidentified.

Letter 3 – Mystery of the Month: Worms in Aquarium may be Planaria

Small Floating Worms in My Warm Water Aquarium
April 13, 2010
Whats that bug please help…i have been an avid reader for at least 3 years now and have seen your both grown to what it is now…i live in Sierra Madre Ca near you if i recall in some posts…. ok to the point i have small worms in my warm water aquarium 82 – 83 degrees they are about quarter inch in length and do nothing but float around and wiggle…what are they?..and how can i get rid of them? …the tank is about 20 gallons and houses 3 algae eaters 1 peacock eel and 2 red crabs..i have another tank same size same temp. no worms only difference is the sub-straight in the tank w/ worms is sand ..please assist . P.S i have no image due to the size and resources to capture the image .. TY
Long time reader first time caller…Sean
Sierra Madre Ca

Hi Sean,
Your aquarium is freshwater and we don’t know if it has plants.  We also don’t know where the sand came from or if there are snails present.  We also don’t know how long the tank has been established, when the worms first appeared, or if there have been any recent introductions to the aquarium.  An aquarium is a closed system, and anything in the aquarium is introduced when things (including plants, animals, furnishings or water) are added by the aquarist, and sometimes organisms may be introduced because they are airborne.  Worms are interesting creatures.  They sometimes develop from encysted larvae like the Gordian Worm or Horsehair Worm.  The North Dakota Department of Entomology website has a good explanation of this phenomenon.  Some parasitic worms prey upon snails, and it is possible that your worms were introduced with snails.  We don’t have a conclusive answer for you, but we will continue to research this topic.

We had some additional thoughts.  You may want to collect a sample and try to have it identified.  You can try Nathalie at Pasadena Tropical Fish on Colorado Boulevard.  If that fails, the Natural History Museum in Exposition Park may be able to answer your questions.  Since your email indicates that they are free-swimming, they may also be the larvae of some species of fly.  They may also be Planaria.  See the AquariumFish website for additional information.

Letter 4 – Gordian Worm

What is this
Location: League city, texas
January 9, 2011 9:02 pm
This snake or worm was found alive at the bottom of our pool after a rain in early January
Signature: Austin

Dear Austin,
This is a Gordian Worm or Horsehair Worm.  It is an internal parasite of certain insects and arthropods including the Potato Bug.  The Gordian Worm has a very complicated life cycle, but it reaches maturity inside the digestive tract of a Potato Bug.  When the worm is mature, it releases a chemical that drives the Potato Bug to seek water.  Once the Potato Bug enters the water, the worm bursts out killing the host.  Adult Gordian Worms mate in the water.

Letter 5 – Help Requested: Wolf Worm Treatments Needed

Wolf worm
February 22, 2012 7:29 pm
Are there any entomologists associated with your site that would be willing to help with some questions regarding wolf worms?  The lady who does the Coveredincathair.com blog rescued a kitten with a wolf worm infection in it’s sinuses…the kitten isn’t doing as well as she would like and would like some additional information.  Thank you for any help you can give.
Signature: Connie

Letter 6 – Mysterious Subterranean Dune Dwellers in Chile

Subject: Worms in Chile’s Atacama Desert sand dunes
Location: Atacama Desert, Chile
November 20, 2013 6:16 am
In the sand dunes of the Atacama Desert, near the city of Copiapo (Chile), I found strange lines near the crest of the dunes. When I looked closer I saw that some of them at one end were advancing. Digging with the finger into the sand I found little worms, not more than 1 cm long.
These dunes only receive some moisture from the coastal fog.
I was wondering what these worms live of and what species they are?
Signature: Gerhard Huedepohl

Hi Gerhard,
We have prepared all of your images for posting prior to doing any research, and we are not certain if we will find an answer, but we really wanted to post your request prior to leaving for work.  We couldn’t find anything quickly, but perhaps one of our readers will be able to provide a comment with a link that helps to solve this mystery.

Hi Daniel,
thank you very much for this message. I have also tried to find information on the web, but without success so far. That’s why I hope really to find out some information with your help.
Lets see, if something comes up.
Best regards,
Gerhard

Hi again Gerhard,
You might want to post a comment to the posting in the event the answer doesn’t come for several years. 

Letter 7 – Mystery Blue Worm is Fishing Lure

Subject: Long blue worm
Location: Dickson, Tn (near Nashville)
July 22, 2014 4:52 pm
Found this worm hanging in an oak tree on July 20 by a silk thread. It is 5-6 inches long and iridescent in the sunlight. Can’t find any info about it, hoping you can help. Thanks.
Signature: Carole

Dear Carole,
We have no idea what this is, but it does not look natural and it appears to have been hung by a human.

So sorry to bother you.  I came to the same conclusion you did  this afternoon as I got more curious and decided to get a step ladder out and touch it.  Turns out it is a fishing lure.  I still have no idea how it got into a tree in my back yard.  My yard is fenced with no gate and I have several dogs (they are friendly).  I hung a chandelier on the next branch over not long ago and the worm was not there then.  I live alone and do not fish.  It is now a new mystery.  Thank you so much for your time.  A friend sent me to your site…it is really interesting.  Again sorry for sending you on a wild goose chase.   Carole

Don’t worry Carole.  Your submission prompted a robust dialog in our comment section and led to some nice links of “real” blue worms in various parts of the world.

Letter 8 – Nematodes in the Laboratory

Nematodes
Location: Albany, NY
November 30, 2010
Thank you for the springtail identification. Um, oops! I don’t think my boss will make me get rid of my plants though thankfully.
We work at AMC in Cell Biology and Cancer research. We have several projects going on here including some Alzheimers research, but my boss likes to look at calcium signaling in the cells and what genes affect it. The worms are transparent, easy to care for, easy to maintain and easy to modify genetically so they make great subjects. The grad students have several projects that they juggle and as a technician I usually have projects that require checking brood size, defecation cycle and crossing strains. I also make and seed the plates with E. coli and try my best not to add any extras, such as microscopic insects. It is a really cool job and our PI is a lot of fun to work with.  I have attached random pictures from our files. I wish I could tell you what strains they are, but they are unlabeled. The green worm is being examined on a GFP microscope. Thanks again!
Cara D.

Hi Cara,
Thanks so much for sending us your photographs of Nematodes and explaining about your work in the laboratory.  According to the University of Nebraska Nematology website:  “Nematodes are the most numerous multicellular animals on earth. A handful of soil will contain thousands of the microscopic worms, many of them parasites of insects, plants or animals. Free-living species are abundant, including nematodes that feed on bacteria, fungi, and other nematodes, yet the vast majority of species encountered are poorly understood biologically. There are nearly 20,000 described species classified in the phylum Nemata .  Nematodes are structurally simple organisms. Adult nematodes are comprised of approximately 1,000 somatic cells, and potentially hundreds of cells associated with the reproductive system . Nematodes have been characterized as a tube within a tube ; referring to the alimentary canal which extends from the mouth on the anterior end, to the anus located near the tail. Nematodes possess digestive, nervous, excretory, and reproductive systems, but lack a discrete circulatory or respiratory system. In size they range from 0.3 mm to over 8 meters.“

P.S.  We are having problems posting your photo taken with the microscope as we cannot convert the file.  Hopefully our webmaster can assist.