Ants in Compost: The Pros, Cons & How to Get Rid of Them

ants in compost
The presence of ants in compost is not in and of itself a problem and, in fact, it can be beneficial. However, you usually don't want them. In most cases, they're a sign that your composting system isn't working. 

Read on to learn the advantages and disadvantages of having ants present in your compost pile and your options to eradicate them.

Ants in Compost – Good or Bad?

The first thing to consider is whether ants are a good thing or a bad thing in your compost.

Like all garden creatures, ants have a purpose. Some ants can be beneficial in composting systems, despite being signs of suboptimal conditions.

Ants in compost – pros

  • Mix compost materials and aerate it
  • Promote good bacteria and fungi
  • Airing the compost with tunnels and chambers  
  • Break down the material
  • Their waste adds fertility

Compost bins benefit from ants in surprising ways. They bring fungi and other organisms into the pile and make the compost rich in phosphorus and potassium.

The ants tunnel through the compost and may extend their colony here, which helps aerate it. Compost aeration breaks down your compost, adds more air to the tunnels, and helps sharp particles break down faster.

Interestingly, ants also eat pests and bring fungi to your garden.

Ants in compost – cons

  • Indicates that the compost isn’t balanced or too dry
  • A few species bite or sting
  • Invades and harms native species
  • Kills some compost worms

The ants themselves aren’t the problem, it’s that they’re a sign that your composting system isn’t working. 

Then there are some ants you don’t want. It depends on where you live, whether you have invasive species or native species of ants.

Invasive species of ants are never welcome, and sadly, you will want to get rid of them before they harm your native ecosystem. 

Why Are There Ants in Your Compost? What Attracts Them?

Food scraps in compost attract ants. A variety of food sources can be attractive to ants, but they are typically attracted to compost that is too dry.

If compost is correctly balanced, moist, humid, and at a higher temperature, ants will not be able to thrive.

Will Ants Kill My Compost Worms?

Some ants are bad for your compost pile’s worms. In large numbers, army ants, fire ants, red army ants, and carpenter ants can also decimate compost worms like earthworms (or larvae). 

So, if there is an ant colony in your compost, you may need to take some action.

How To Control Ants in Compost

The compost ecosystem should be filled with life, and a few ants aren’t always a problem. Instead of getting rid of them all, you might just want to control their population if they’re a good type for composting.

You can control ants in compost by keeping it wet enough, choosing a different composting method, or adding more nitrogen-rich materials. They may still be around, but their population won’t explode.

There may be times when you want to get rid of ants if they’re invasive or particularly problematic in your garden.

If you want to get rid of ants from compost, drench it with cold water, add cornmeal, or use diatomaceous earth or nematodes. Cornmeal can also benefit your compost, giving microorganisms in the system food.

There are certain specific nematodes that are effective against certain ant species, but you have to know what species you’re dealing with and choose the right biological control.

How To Avoid Ants in Your Compost

To avoid ant infestation, keep your compost pile moist and aerate it frequently to prevent ants from entering.


Discovering composting as a way of life or even better, as nature’s way of recycling, Ana dedicates her time to trying out new methods of composting at home. Her goal is to share everything that she’s learned in the hopes that it will help others discover the amazing rewards of composting.

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