To those of you who are new to the world of composting, a compost bin is where you store all your organic materials so that they can decompose and be turned into fresh compost which is rich in plant nutrients as well as other beneficial organisms. Composting has recently become popular as people work towards becoming greener in their everyday endeavours. Being conscious of the environmental ramifications of your actions is now essential and using a compost bin is both easy and fun! While composting, a common thing you might find is ants in the compost bin. A common question in this scenario is whether ants are good or bad for your compost? The answer is a little more complicated than just classifying ants as completely good or completely bad.

Ants in the Compost Bin. Is it Good or Bad
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Are Ants in a Compost Bin Good or Bad?

Ants have a unique part to play in the process of composting and they can also indicate whether you are doing something wrong and whether you need to pay more attention. A small number of ants is nothing to worry about however if there are loads, you may have a problem.

A Small Number of Ants

A few ants in the compost bin will not do any harm. They are actually good for the compost you are trying to create. Ants bring fungi and other helpful organisms that the compost needs which helps ensure that the compost is fresh and rich in minerals like potassium and phosphorous. The constant moving around also helps with aeration. What this means is that the holes ants dig to move around, give the compost heap inside the bin room to breathe and grow. The presence of the ants also keeps away other more harmful insects. They also make their own waste, which adds to the compost pile, making it healthier and richer in protein. 

A Large Number of Ants

A large number of ants or if you have a colony that has set up a home in your dalek means that your compost bin is too dry. Hence, you should quickly add some water to it, allowing it to become moist. Make sure not to waterlog it though! Just add enough water so that the compost becomes fresh and not dry. A good example of how moist it should be is that of a wrung-out sponge. Make sure that your compost only has enough water so that if you squeeze a pile of it in your hand, only a few drops of moisture fall out and nothing more. 

Red and White Glove Turning Compost Over with Garden Fork
Compost Being Turned Over

Why Are Ants Attracted to Compost?

Ants are attracted to compost bins primarily because of the abundant food sources they provide. As organic materials in the compost begin to break down, they release sugars, proteins, and other nutrients that ants find delectable. These materials can be remnants of fruits, vegetables, grains, or other decomposable items that have been discarded. Additionally, the moisture content in compost bins creates a favourable environment for the growth of fungi, bacteria, and other microorganisms, which ants may also feed on or use to farm their primary food source: aphids.

Aphids excrete a sugary substance called honeydew, which is coveted by many ant species. In essence, compost bins present a buffet of food opportunities and a suitable habitat that can support a thriving ant colony.

How to Remove Ants Nest from Compost Bin

If a colony of ants has made a nest in your compost, it is too dry so you will need to moisten it as mentioned above. Another way to ensure that the ants do not hang around is to get into the habit of turning at least once a week. Turning is a great way to aerate your compost and help along the process, the added bonus is that ants do not like to live in soil or compost that is regularly disturbed so they will up and move on.

How to Keep Ants out of Compost

The trick to keeping ants away from setting up a home in your compost is to keep it healthy. Ants do not like conditions to be too moist and they certainly do not like to be disturbed when the compost is turned and aerated. It is also said that ants are attracted to compost by smell – the worse it smells the more ants it will attract. Here are two tips for keeping your compost odour (and ant) free.

1. Make sure your compost is getting oxygen!

A lot of the time, compost bins start to smell because the decomposition happens anaerobically – i.e., without oxygen. This can happen if you have many dense layers of compost stacked on top of one another. The layers below get no oxygen which leads to faster decomposition, foul odour, and more ants.

Try using a wider, rather than taller bin for storing compost. Also avoid stacking a lot of flat compost materials (such as banana peels) on top of one another, as it will block air from reaching the materials below. This will allow each layer to have a bit more breathing space, through which oxygen can pass through.

2. Use just the right amount of water!

If you use too much water in your compost, your compost ingredients will get soggy and the compost will start emitting a foul odour, which can attract ants. If you step on a bit of compost, and more than a few drops of water seep out – your compost is too wet. Tone down how much you are watering your compost and if it is raining a lot, cover your compost with a tarp or lid – just make sure the lid is not fully closed, or you are going to be running into problem #1, a lack of oxygen leading to foul odour.

Ants and Compost Pile
Ants and Compost Pile

Are There Any Benefits to Having Ants in Your Compost?

Yes, there are several benefits to having ants in your compost bin:

  • Aeration: Ants are natural tunnellers. As they move through the compost, they create channels, which improves aeration. Proper aeration is vital for the efficient breakdown of organic material, as it aids in the distribution of oxygen, which is essential for the aerobic bacteria responsible for decomposition.
  • Speeding up Decomposition: Ants carry organic material into their nests, breaking larger pieces into smaller bits. This action accelerates the decomposition process by increasing the surface area of the material, making it more accessible to microbes.
  • Predation: Some ants are predatory and feed on pests that might be harmful to the composting process, like certain fly larvae and other unwanted critters.
  • Distribution of Nutrients: Ants transport and mix different particles in the compost. This can help evenly distribute nutrients throughout the compost pile, leading to a more balanced and rich compost.
  • Indicator of Dryness: If you see ants colonising your compost bin, it might indicate that your compost is too dry. Ants usually prefer drier conditions, so their presence can be a helpful reminder to maintain the moisture levels in your compost.

However, it’s worth noting that while some ants can be beneficial, an excessive number of ants, particularly invasive species, indicates an imbalance in your compost. It could be a sign that the compost is too dry or that there’s too much easily accessible food. In such cases, adjustments to your composting practices may be necessary.


Ants in the compost bin are a common occurrence. So common, that it is normal. The only thing that you should keep an eye on is the number of ants in the compost bin. Too much is not good, but a little will not do any harm. Ants can do wonderful things for your compost if the balance is right. Once you have got an ant infestation, it is time to put the anti-ant strategies you have read in this article to good use.

How to Keep Ants out of Your Compost Bin? Infographic

Garden Doctor Tips

“You should turn your compost weekly to keep the compost aerated and prevent ants from setting up their home as they do not like to be disturbed!”

“Keep your compost moist but cover your compost bin in the winter to prevent it from becoming too wet and waterlogged!”

“Add some used coffee grounds to your compost, ants are not fans of coffee. If you are not a coffee drinker, ask your local costa for some of theirs!”

Frequently Asked Questions

How to keep ants out of compost?

The best way to keep ants out of compost is to keep it healthy and moist. It is also a great idea to add a generous amount of used coffee grinds. Ants do like wet conditions and they are also not fans of coffee

How do I get rid of ants in my compost?

If you have ants in your compost, it is a sign that it is too dry. You should wet the compost so that it becomes moist and give it a good turn.

Compost should be moist to the touch with no more than a couple of drops coming off when squeezed.

Is it OK to have ants in my compost bin?

It is okay to have a small number of ants in your compost bin although it is not a good sign if you have a nest or colony move in.

Too many ants are a sign that the compost is too dry and needs moisture. To get rid of the ants, add water and turn the compost.

How much water do I add to my compost?

If your compost is too dry, you will need to add some water. Once wet, the compost should be moist to the touch with only a couple of drops coming off when squeezed. Do not add too much water as this will cause the composting process to slow down and can make the contents smell bad.


Trevor Wright is not just a seasoned horticulturist; he’s the esteemed Garden Doctor. With a BSc in Horticulture and years of hands-on experience in the soil, Trevor has become a trusted mentor for all things gardening. As the founder of Garden Doctor, he’s committed to clarifying the intricacies of gardening, offering straightforward advice that’s rooted in years of practice. His writing is a garden of how-tos, savvy insights, and comprehensive guides that enable individuals to nurture and grow their garden dreams. When he’s not knee-deep in garden beds, Trevor is at his keyboard passing on his green-thumbed wisdom to budding gardeners, ensuring that the legacy of sustainable and joyful gardening blossoms far and wide.

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