Why are ants coming from under my toilet & around the toilet base?

There are these black ants coming from under my toilet and I don't know why. Food sources? Stagnant water? Bathroom flooring issues? I find these tiny ants in the toilet bowl, around the toilet, and under the toilet, but seems like they're attracted to or coming from around the toilet base.


I think they're just carpenter ants but not sure the best way to get rid of them. Any pest control/infestation advice is much appreciated.

  17 answers
  • Ants are attracted to dark, damp places. They are also attracted to drains and everything that's in them. Make a solution of 2/3 water, 1/3 dish soap in a spray bottle. Add a few drops of peppermint oil, shake and spray around the base of the toilet.

  • Seth Seth on May 03, 2023

    Is this a first floor bathroom and do you have access to a basement or crawl space to be able to see under the toilet? If not, I would suggest removing the toilet to determine if there is a slow leak or rot issue that might be attracting the ants. It might just be the way you took the picture, but that ant looks too small to be a carpenter ant. What is attracting the ants may be more of a problem than the ants themselves.

    • I'm on the third floor, which is the top floor of my building, so I'm a bit surprised about the ant problem. There's a bathroom in the same spot on the two floors below though, so it could be an issue coming up from one of those. I'll speak to my neighbors and see if they have the same ant/toilet issues before removing anything.


      Agreed, the ants are tiny, but they looked most like carpenter ants as far as I could tell from looking at images online.

  • Kathy Gunter Law Kathy Gunter Law on May 03, 2023

    Probably looking for water. Check to make sure all cracks are sealed like around the base, plumbing, windows, etc. You can sprinkle diatomaceous earth around the area and it will kill them on contact. If you have small children or pets get the food grade and it is completely safe, even if eaten. Tractor Supply & Lowe's carry it. Not sure where else you can pick it up.

  • William William on May 03, 2023

    You can check with your neighbors if they have the same problem. The ants may have or are building a nest under the floor. Nearest exit is probably under the toilet. I would get some indoor bug spray and saturate around the toilet. Removing the toilet would help. Better access.

    • Yes, I checked with the neighbors, but they weren't sure. Both said they notice the odd ant every now and again, like every summer, but that they hadn't noticed many, and not loads around their toilets. Perhaps they just haven't noticed - they said they'd look out for them.

  • Cheryl A Cheryl A on May 03, 2023

    they look for food and water if you have a leak or seeping from your toilet that could be the cause- you can remove the toilet and change out the toilet ring around base of toilet and then see if you see a leak -

  • You'd know a carpenter ant if you saw it, they're super huge. For the why, that's tough to say but they're getting in from outside and finding their way out here. Sprinkle some diatomaceous earth around outside the perimeter of your house then get some Terro liquid bait traps for indoors. The traps will solve the indoor problem near instantly.

  • Dee Dee on May 03, 2023

    Carpenter ants can be found nearly anywhere in North America. Although they don’t eat wood, they tunnel through it to create hollow areas for their nests. If they get indoors, they’ll begin at spots with moisture damage, but from there, they can get into stronger wood, eventually weakening it and causing serious structural damage.

    • Hi Dee, I think Becky is right - they can't be carpenter ants as they're really tiny. I hope these little ones don't cause that kind of damage!

  • Dee Dee on May 04, 2023

    f you notice ants floating in the toilet tank, they might be coming with the water from the pipes connected to your home. If that is the case, it implies that the source of water is the one that is a problem, and what you see in your home is the result of the contaminated water. invest in a water filtering system and install it on the line to your home’s water supply. This will help get rid of the ants.


    f you are suspicious that you are a victim of ant infestation, you will need to do a thorough investigation under the toilet bowl and behind the toilet tank. If there’s an infestation, you will see some ants sticking on the edges of the toilet lid. You might also notice some ants scattering in different directions.


    If you’re not sure where the ants are originating from, you should follow the ant queue, and that will lead you to gaps or cracks on the wall or floor where these ants might be hiding.

    However, in most cases, you will notice holes around the toilet bowl. These holes act as an entry point for the ants when getting into the toilet tank. This is why it is important to seal any visible holes in order to stop the ants from getting into your home.

    The first step you should take if you notice ants in your toilet seat or anywhere else is to disinfect. Disinfecting the bathroom is one of the best ways you can use to ensure that you keep the ants at bay. The reason being is that the chemicals used will repel the ants.

    After you have disinfected the bathroom, the next step is to check for any gaps or cracks that might be behind the wall or the tank in your bathroom. If there are holes, you should seal them right away to prevent ants from getting in. And it doesn’t matter how small the holes are, you can be sure the ants will dig their way through them.

    Another way you can get rid of the ants in your toilet area is by spraying the bathroom with an insecticide. However, you need to be cautious about the product you purchase since some insecticides are harmful to the environment and can also be dangerous to your health.

    If all else fails hire a pest control company.

    • Amazing! Thanks for all the info, Dee! I'm already being pretty strict with cleaning and disinfecting, which has helped, but still some ants. Yes to insecticide, but I have a cat, so I'm mindful of any chemicals affecting his health as well. So, I'm trying the peppermint oil suggestion from Ann for now. If it's still a problem after a week or so, then I'll try a chemical one and keep my cat out of the area.


      Thanks for all your help!

  • Mogie Mogie on May 06, 2023

    Consider upping your cleaning routine and keeping the area in and around your toilet especially clean. Even a quick wipe with a disinfectant every day should help curb the problem.

    I also read something a long time ago that ants near a toilet signal, believe it or not, diabetes in a household member. The urine has a high glucose content. But that's a super long shot.

  • Hi Amy! Ants need water to survive and are attracted to damp or moist environments. If there is a water leak or standing water in your toilet, this could be attracting ants.

  • Mogie Mogie on Jul 09, 2023

    I watched where they were coming in and caulked that area. Haven't had a problem since.

  • Samueldaisi Samueldaisi on Sep 08, 2023

    I totally get how alarming that any situation can be! There could be a few reasons – maybe they found some water or crumbs around, or there might be some hidden wood they're into. Last summer, I had a similar ant invasion in my kitchen, and I tried all kinds of home remedies, but those little critters just wouldn't budge. It was driving me crazy! In the end, I decided to reach out to professionals, and I found this pest control service at https://ajverminatorpestcontrol.com/. They were quick and effective in getting rid of the annoying ants for me. So, maybe considering a pest control service could be a great solution for you too!

  • Dee Dee on Sep 12, 2023

    Peppermint essential oil will get rid of ants. Mix with alcohol and water. Spray around toilet and put some down the drain.

  • Deb K Deb K on Sep 12, 2023

    Hi Amy, hope this helps you out. Those are not carpenter ants. That being said, there should not be ants coming out from under the toilet. Ants are attracted to dark, moist spots with water and food, so the bathroom is an ideal spot for them to nest. You can prevent ants from congregating in your bathroom by properly cleaning. Some household products can work as an ant eliminator, but you may have to call an exterminator to get rid of the infestation.

    Preventing an ants-in-bathroom nightmare is simple, at least on paper: make your bathroom less hospitable for ants. Get rid of their food, their water supply, and the other creature comforts that ants adore.

    • After a shower, make sure steam can get out of the bathroom. Turn on the overhead fan (if you have one) and leave the bathroom door open
    • Keep the bathroom clean, and don’t forget bathroom tiles and shower curtains
    • Use an old rag or cloth to sop up puddles of water
    • Don’t just empty the trash bin in your bathroom, but clean it out with soapy water and rinse it thoroughly, too
    • Mop regularly, and don’t miss that strip behind the toilet. If your sink is on a pedestal with free space behind it, mop there as well
    • Make sure caps and lids on soaps, perfumes, toothpaste, and deodorant are secured properly
    • Regularly unclog the sink and the bathtub
    • Thoroughly and regularly clean shower mats, and replace them if they get even mildly funky
    • If ants are coming up through the drain, it’s a strong indicator you have a leaky pipe somewhere and should call a plumber
    • As needed, seal up cracks under window frames and repair and caulk tiles


  • Patti Pacifico Patti Pacifico on Mar 29, 2024

    I had a full blown army marching from under my toilet to the tank. The bolt had rusted and the tank was loose.

    There are massive ant colonies in my yard and there was no sealant around any of the trimming in any room. I know people go straight to chemicals (other than the peppermint oil) but I see no reason to kill them, if possible. The ants are just doing what they are meant to do.


    The BEST solution that I found was to put Vaseline in a plastic baggy and trim the tip of a corner as you make an icing bag. Squeeze the vaseline out of the trimmed corner & smooth along floor & wall trim or the wall and counter where they meet. The ants can't or won't cross the Vaseline & they find their way to the door or sweep them up & throw them out. Why kill any creature when you don't have to do so?

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