Red Ants In Worm Bin

Here is a question from Karla,

I live in Texas where the red ants are always a problem.
Well at least once a month I find them in one of my bins. My bin or
kept on the deck in the back yard. Will they eat my worms? What can I
do to keep them out? Will ant killer, kill my worms?

Hi Karla,
Ants are a common pest in outdoor worm bins. Generally, if you maintain ideal conditions for your worms however, they shouldn’t create too much of a problem. Ants prefer much drier conditions than worms, so keeping your worm bed nice and moist (assuming good drainage) is a good start.

Ants also tend to be much more interested in the food scraps in a worm composting system than in the worms themselves. That being said, aggressive species like fire ants can probably cause some issues if abundant enough.

I definitely would NOT add any sort of ant killer to your worm bin – this could definitely harm or kill your worms, not to mention the rest of the compost ecosystem. Aside from keeping the system moist, perhaps you could try some other strategies to discourage the ants from coming in to the bin in the first place. Try setting up a perimeter of diatomaceous earth on the ground around your bin – this should greatly harm any ants that try to cross it, since it is essentially like a field of broken glass for bugs (ouch!).

You may also want to try some other relatively innocuous deterents. Put some honey mixed with borax in shallow dishes near the bin. The ants should start focusing on this pretty quickly, and when they take this material back to their nest, it can end up killing off a lot more ants.

If you know the location of ant nests on your property, you might try pouring boiling water on them – not the nicest thing to do (haha), but when push comes to shove, you gotta do whatcha gotta do!

Hope this helps!

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    • Sherry
    • April 17, 2009

    Hi Karla,
    I’ve read where you can set your bin on posts or some kind of support, with the legs in cans of water. The ants will drown. Definitely worth a try, anyway!

    • Sara
    • April 20, 2009

    Hi Karla ,

    Most of bin were located on top of a iron stand , dip legs in cans of oil ..any oil … water may cause mosquito breeding and may dried out if not fill up regularly. Using oil is a 1 time deal. Try it.

  1. Karla,

    Try boric acid, (simple powder form found at most stores these days and mix 1/3 boric acid, 1/3 peanut butter and 1/3 sugar and mix. As most ants can change their appetite wants and needs, this mix gets those looking for sweats as well as oily substances.

    A mixture which is too weak will kill nothing. A mixture that is too strong will kill the ants prior to making it back to the nest hence not eliminating your problem.

    The mixture above will permit the ants to pick up food and bring back to the nest, eventually killing off the colony.

    If you try Sara’s comment above, be sure to place something under the legs on your deck as any oil will stain the wood, even if sealed.

    Good Luck,


  2. If I use diatomaceous earth to control flies in my barnyard (goat/chicken) can I use this aged manure in my worm bin? Will the d. earth kill my worms?

    • Bentley
    • October 19, 2009

    Never responded to this one – thanks everyone for chiming in! Very helpful advice.

    ELIZABETH – that is an excellent question. I am not really sure, to be totally honest with you. This material is often referred to as totally ‘harmless’, ‘eco-friendly’ etc – but I don’t think people ever think of worms when they come up with these designations. Given the fact that it is like adding a heap of tiny glass shards, I would think that there might be a decent chance of this stuff being harmful – after all, if the hard exterior of an insect can get damaged, why not the soft body of a worm?
    Hmmm…definitely something I myself would like to know the answer to.

    • cbw1953
    • March 28, 2010

    Regarding DE:

    A unique, naturally occurring mineral deposit which typically contains 65% Diatomaceous Earth (skeletal remains of algae) and 35% Montmorillonite (calcium rich volcanic deposit).

    Worms Etc uses this product to reduce fruit fly and other insect populations. It is an all natural solution for a big problem.To use just spread a very fine layer on the surface of the worm bed. It does not take much at all, but it is completely safe for the worms. Before we used it at worms Etc we tried growing worms in highly concentrated mixture of diatomaceous and bedding. The worms just ate it like any other bedding.

    Diatomaceous earth is also very useful for control of pest on plants. Instead of using chemical pesticides in your garden, especially if it is for consumption, try using diatomaceous earth. It is very effective and completely benign. Some people even put it on their cereal in the morning for arthritis or other ailments. Worms Etc is not suggesting this however.

    This is food grade diatomaceous. Do not use pool filter media diatomaceous earth, as it is different.

    • Shawn
    • March 10, 2012

    Question for you experts…

    Two of my outdoor bins are heavily red ant infested. One is vermi, one just regular compost. The ants actually built their colonies inside the bins as opposed to just traveling there for food. If I use a borax mixture to eliminate the colony, will that add too much borax (inside the dead ant bodies) which might get into the whole compost ecosystem? When the worms consume the dead ant bodies will they also die? I’ve tried citrus and vinegar which hasn’t seemed to work…now I’m trying to drown them out, but borax I guess is my last resort. As soon as they’re gone everything’s going on stilts. Thanks for the site Bently (and everyone else!)

    • joanne
    • June 11, 2014

    I just started composting in our backyard and am ready to add in some red wigglers. However, when I noticed that my compost is swarming with ants. How do i get rid of the ants? I’m afraid that once I add in my worms, the ants will attack and destroy them.

    Thanks for the help!

    • Tiffany
    • July 13, 2015

    We have been breeding worms for over 3 years now and have had a few set backs, but have also made great strides. I really enjoy doing this, but this year for some reason we have been invaded by fire/red ants. We live in Florida, and was approached by a local gardner to move our bins to their facility for our and their benefit. But after moving them, the ants started coming in. I do not want to harm the worms, but need to get rid of the ants. Have never had this issue. I have read a few articles of a few possibilities, and seem to be keep coming back to borax and honey/syrup. Any suggestions would be helpful.

    Thank you in advance, Tiffany

  3. Hello,

    I have been worm composting on a larger scale for nearly 20 years now and one of the recurring questions I received was the concern of worm bin owners about the invasion of ants into their worm bins. as Bentley mentioned ants don’t like a wet environment and a humid and moist worm bin setup is somewhat discouraging to them but very often they still find a way into a worm farm full with nutritious organic materials that the little insects would love to feed of. Most ant species are competing with the worms for their food and are not a direct threat to them. Some varieties though like “Army ants, Red fire ant and the “Carpenter ant” are exceptions to this rule. Once a worm farm has been invaded by an ant colony a good way to get rid of them away is to flood the bin with water. Depending on the size of your bin pour several liters or up to a gallon of water over the surface of the worm food and worm bedding which will will make the ants extremely uncomfortable and they will as fast as they can try to get out of this wet environment to look for dry pastures. As long as there are enough working drainage holes in the bottom of the bin the worms will not be in danger of drowning at all. They breath through their skin and can life for extended times suspended in water as long as it contains enough oxygen. The flooding should take care of the ant population for now but ant colonies are constantly sending out scouts that are in search of new food sources. So sooner or later the same or another ant colony might invade your worm farm again if given the chance.

    The in my opinion best way to keep ants out of a worm bin for good if it is placed outdoors is prevent them from entering in the first place. So developed worm farms that I called worm farm islands. It’s a fancy description for worm bins that are completely surrounded by water. Similar to many of the old castles in medieval times.It’s really easy and cheap to set up and is virtually foolproof. You just need a container that is at least a little bigger than your worm bin a few bricks and some water. I set one of those worm islands up in less than five minutes and have been running some of them for years. So far there hasn’t been an ant invasion in any of them. Ants can’t swim. I have published an article with pictures about that subject which should help you to keep your worm herd safe from ends from now on. All be best to all you worm composting enthusiasts and happy worming.

    Kind regards


    • Kim Houston
    • January 5, 2020

    Does it take a while for the borax mixture to kill off the ants? I used it, and the ants were all over it, but I think they are on to it being poison.

    • Jennifer Wolfe
    • June 7, 2020

    I use grits, just cheap raw grits. Kills the fire ants i get. Doesn’t seem to bother the worms. I use them in my yard, i have kids & pets, didn’t want poison in the yard

    • Margie
    • July 24, 2021

    Thanks Bentley for maintaining this website! I’ve had my vermicompost bins starting from an initial mail order bag of worms for more than 10 years now! Your website is always a great place to get more info.
    In case this helps other readers:
    I have an infestation of “sugar ants” in two of my smaller bins that I normally kept in our sun room. I’m very concerned about the ants getting into my main bins in the garage, so I wanted to figure out a way to try to remove the ant nest within the small bins. My ant problem is NOT large, so I hope I can get on top of things.
    The advice in the comments here have been really helpful. I really like the info provided by Stephan. I don’t actually have drainage holes on my plastic bins – I’ve always been able to modulate the moisture in my bins by adding dry bedding such as shredded paper.
    So… in case anyone else has indoor bins withOUT drainage holes PLUS an ant issue, this is what I am trying. (This won’t work with aggressive ants that can bite humans).
    I dumped the compost into a bigger bin that *does* have drainage holes (maybe if you want to make something temporary use an old large plastic bag with holes cut into the bottom). I used the “mist” function to wet my compost. I mixed it all up and let it sit. I’m hoping that the ants won’t be able to rebound from this stress – the ant eggs and larvae should be disrupted from the wet + mixing. The whole thing was almost too much, I was worried that the worms would possibly suffocate from lack of O2 flow when put back into the bin . Thus, I shredded some paper and added it in until moist but not sopping.
    Yes it feels super weird to “wash” and then “dry” my worm compost. I’m hoping I won’t have to do this more than one more time.
    The entire (small) infested bin is now sitting in a larger bin filled with soapy water.

    I’ll try to post again with an update whether this finally works or not. I can’t bear the idea of throwing away a perfectly good bin of worms due to some sugar ants nesting in the compost!!!

    • Margie
    • September 27, 2021

    Update about the “wash and dry” method for combating tiny black ants:
    So the method I described above actually worked well!!! Yay, thank goodness!

    Quick summary: I used the “mist” function on a outdoors water hose to really wet down the worms + compost. I did this in a container with drainage holes- DO NOT DROWN your worms! Mix, mix, mix to really agitate the whole system, this seemed to disrupt the ants ability to care for their eggs and larvae. If the result is too sopping wet, add shredded dry paper to help absorb some of the extra water. If you normally used a closed system without drainage, return compost to original bin.

    Ants usually follow a scent trail, so I moved the entire bin to a new location AND I made a soap + water trap to surround the bin. I didn’t want the stressed out ants to leave this “infested” bin to find a better place and just set up a new colony elsewhere!

    I did this twice over the course of a month and was able to get rid of the ants. Of course, the mite population exploded b/c of all the extra moisture, but they are easier to deal with. This site has plenty of good tips for mites! Good luck! Oh, for context, this was NOT a very large infestation of ants. But they can get out of hand quickly, so I was happy to stop the problem before it became horrible!

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