Ants in Compost: Pros & Cons, How to Avoid & More

Red ant in compost soil

Ants in compost heaps can be beneficial if you handle them with the proper approach and make sure you limit your compost pile to only healthy ants. In addition, you'll need to control ants like fire ants that may attack your compost worms or cause other problems with your compost heap.


Your compost pile attracts many beneficial insects, such as worms, that help compost your food scraps and create healthy compost. But when you get ants in a compost heap, you may understandably worry. Are these insects good or bad for your compost pile, and what can you do to control them?

Let's look at how ants affect your compost bins and whether they hurt your compost worms.

Are Ants Bad For Compost?

A group of red ants in a compost heap

Here's something that may surprise many composer makers: ants aren't necessarily bad for your compost pile. In fact, a few ants in your compost bin may even be a good thing. They provide many benefits that we'll talk about a little later when outlining the benefits of ants in your compost tumbler.

The short-short version is that they bring fungi to a compost that helps create potassium and phosphorous. Beyond helping to bring fungi to compost, ants even help with aerating your compost and may even improve the composting process in some ways. That said, many ants may indicate a more severe problem that needs to be addressed. For example, you need to know how fire ants can attack and even eat worms.

You also need to know the ways carpenter ants can help by composting woody materials in your compost heap, which may help give more fiber and nutrients to your late spring composting pile. So, are ants beneficial creatures for the composting process, or should you deter ants or even kill ants in your compost pile?

But, first, let's address the big problem: what happens with worms in your compost pile when ants invade? Are they in danger?

Will Ants Kill My Compost Worms?

Red ants crawling on top of a branch of tree

Let's get this out of the way first: very few ants will deliberately attack or kill worms and other insects in your compost pile. Most ants that you find your compost is there not to hunt and kill worms but to look for Food. Furthermore, many ant species are attracted to and eat the same food types that a worm composter eats. As a result, you may not need to discourage ants or kill ants in your heap.

That said, some ants will kill young worms and take their eggs to their colony as a food source. These more aggressive ants may not attack large worms due to their excessive size but can stop your juvenile worms from reaching their full potential. Similarly, even non-aggressive ants may kill your worms simply by competing for Food in your compost and causing starvation.

Are Ants Good Or Bad for the Garden?

Two red ants crawling on green leaves

Ants are generally suitable for your garden, even ants in compost. That's because ants aerate the soil and redistribute nutrients throughout your garden. They can perform many of these same roles in compost piles and even help provide a suitable food source for various animals in your yard.

Birds and other animals eat carpenter ants, fire ants, and other ant species in your garden. That said, there are a few concerns that you might run into when ants hang out in your garden and yard.

First, not every ant species is beneficial for your garden. For example, army ants can be very destructive by digging up your ground and affecting your plants' roots. Carpenter ants also directly attack various plants and even trees and chew on their green material. Other ants are attracted by plant debris and may leave their waste behind on garden plants. However, they also bring healthy fungus to your compost heap and may crack apart some food materials.

So generally, ants are not a bad thing in your garden, as long as they aren't directly attacking your garden plants or damaging your soil.



Ants in Compost Pros & Cons

Four compost bins with different colors

When deciding to get rid of ants in your compost pile or compost bin, it is essential to know more about the benefits and disadvantages of letting them hang out in your compost tumbler.

Later on, you'll learn which ant types aren't good for your yard and how to control ants using a few simple methods.

Benefits of Having Ants in Your Compost

Ants provide a surprising array of benefits to your compost bin. For example, ants help increase biodiversity by bringing fungus and other unique and beneficial organisms into your compost.

Add More Microorganisms

Two hands holding compost soil with worms

They bring new materials into your compost and help compost other new food materials, including green and brown materials. These microorganisms can help compost your pile further and create a healthier range of food times that may keep natural predators and invasive species away from your compost pile.

Aerate Soil

Person holding a handful of soil dirt from wheel barrow

Ants also tunnel throughout compost and may extend their colony here, which helps aerate the compost more.

Aeration helps break down your compost, adds more air to the tunnels, and helps sharp particles in your pile break down more quickly. This process may help retain moisture in your compost and help your organic material and kitchen waste break down in your pile. Your moisture level needs to stay strong like this in your pile to attract good bacteria and keep out pests that may affect your compost.

Pest Control

A maggot fly on top of a green leaf

Interestingly, ants also prey on harmful pests while bringing fungi to your garden and compost. This process gets rid of unwanted insects and pests and protects the plants around your garden.

Are Ants Bad for the Compost Heap?

Black red ants on a soil

There are times when you don't want ants in your compost pile and breaking down your organic matter or affecting your moisture level by aerating the soil. Here are a few ways that ants may be bad for your compost.

Note that you can use treatment methods like parasitic nematodes, diatomaceous earth, sticky traps, cold water, and even boiling water to keep ants out.

Impact Worm Health

A worm on the grass

While it is true that most ants don't directly attack the worms in your compost bins, they can affect your worms in many ways. For example, they can take away the worm's food sources and cause your worms to struggle to compete by comparison.

Remove Food From the Pile

Man getting compost materials from compost bin using a shovel

In addition, ants are far more mobile and voracious eaters than worms, meaning that they are likely to carry away the Food and not compost in your heap.

As you can imagine, this problem will affect your organic matter, potentially attract pests, minimize your healthy fungi presence, and even let ants spread their nest and other material items into your compost.

Protect Aphids

A group of green aphids

Even more surprisingly, ants can adversely affect your pest control and protect aphids, which may affect your garden's health. You may want to get rid of ants and their nests near your compost heaps in this situation to protect them.

Even when ants don't eat your worm population, it might be necessary to get rid of ants and keep your garden safe. When you get rid of ant nests, it is essential to know which to treat. Not every nest of ants is harmful, and some are far more problematic than others.

Which Ants Are Not Good for Your Compost?

Black army ants on a wood

Ants you want to keep out of your compost heap include army ants and other aggressive species.

Any ants that eat worms or have a carnivorous appetite should be avoided. You may also want to avoid any ants that guard aphids in your garden, as this may affect your compost. Fire ants should also be avoided, as fire ants can be very aggressive, attack worms and other beneficial creatures, and cause various other troubles.

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

Group of ants crawling on a piece of bread

You typically won't have an ant problem if you keep your moisture level good in your compost pile because ants only invade when it dries out. When the ants notice that your compost pile is dry, they will get attracted by things like coffee grounds and other rotting materials.

So if you've ever asked, "does coffee attract ants?" there's your answer. Coffee grounds are a surprisingly popular ant food, partially because coffee grounds improve their metabolism and give them more energy. In this way, coffee grounds work like usual coffee does for people, which is pretty amusing to consider.

But what about other types of foods, like vinegar? Does vinegar attract ants?

Not at all, which may seem surprising. However, most ant types hate vinegar smells and avoid them whenever possible because they're far too pungent for an ant's delicate nose. That said, ants are heavily attracted to sugary compost heaps and will eat foods in them, including bread and complex carbohydrates that will compost to sugary materials. In this way, the rotting and composting Food in your pile will attract many ant types ready to eat, including those ants who want to eat worm species.

How To Avoid Ants in Your Compost

If you don't want ants in your compost and aren't sure how to prevent them, the following steps should help. Most of these steps are preventative, meaning that they're designed to stop ants from ever getting in your pile. The next section will include measures for getting rid of an active ant infestation.

Use a Protected Bin

Person covering the gray compost bin

If you want to keep ants out of your compost, use an ant-proof trash can or another similar item to keep them out. You may also use Lomi, a home-based composting system that you can store inside of your house and seal against ants and other types of invasive creatures.

Lomi by Pela



Lomi allows you to turn food waste into plant-ready nutrients in under 24 hours. Boost your plants while reducing your waste.

Spread Specialized Treatments

A closeup picture of red ant

Treatment methods like diatomaceous earth and boric acid can help keep ants out of your compost pile and ensure that it remains safe. You can also consider oil-based treatment options that help keep ants out of your compost pile and ensure that they don't cause more problems.

Add Extra Moisture

Group of red ants in a dark soil

When all else fails, you can always keep your compost moist by adding either cold water or boiling water to your heap. The cold water helps keep the compost properly, while very hot water may kill ants. However, it may also kill your worm population, so be careful here.

Manage Your Heap Properly

Person putting organic waste to compost bin

Make sure you mix your compost regularly to help minimize the possibility of scents spreading and attracting ants to your heap. Keep the temperature between 60-72 degrees Celsius or 140-160 degrees Fahrenheit. Direct sunlight helps keep this temperature, though Lomi also helps here by creating consistent temperatures.

How To Control Ants in Compost

When ants get out of control in your compost, and you want to get rid of them, there are a few steps that you can take to manage this situation. Thankfully, most of these steps remain pretty straightforward and shouldn't take too much time to get right.

Use Nematodes

Person in white gloves holding a petri dish of Nematode

Nematodes in your compost will directly attack your pests and kill them whenever they try to enter your heap. However, they aren't dumb and know precisely what these nematodes do, meaning they'll avoid your compost heat as much as possible. Nematodes also attack other insects but not your worm population.

Add Water

Zinc watering can pouring water into the garden

As mentioned before, water can frustrate your ant population and keep them away from your compost. Colder water will cause them to either drown or freeze to death, while scorching types boil them alive. Pour this water into the ant nest to get the best results.

Integrate Other Methods

Crushed three quarter inch limestones

Things like crushed limestone can neutralize your heap's pH level and keep them away. Coffee spread away from the pile may attract them in other directions, while cornmeal can safely kill them without causing pollution. Ants can't digest grain but will eat it and, as a result, die.

Making Sure Things Go Smoothly

As you can see, ants in your heap aren't necessarily bad and can even help with the decomposition process. However, ants in your pile also show that your compost heap needs a little moisture and may be drying out. So, take the steps above to get your compost working smoothly again, or get Lomi to simplify this process and control your ant population in your newly balanced heap.