Why do Ants Build Mounds? (And How are they Built?)

Ant mounds exist for various reasons. They protect the nest underneath, act as a safe entrance for the nest, and even help in the regulation of the nest’s temperature and humidity.

Ant mounds are built by the tedious labor of the worker ants who deposit huge piles of underground soil at the nest entrance.

Why do Ants Build Mounds

In most instances, ants do not live within the mounds themselves but in tunnels and chambers constructed underground right below the ant mound.

What are Ant Mounds?

Ant mounds are large deposits of soil on the ground that act as the entrance to their nest.

These are deposited on the exterior of the ground by the worker ants and the mounds act as proof that an extensive amount of tunneling has already been done underground.

So basically the worker ants carry the excess bit of soil which were produced owing to tunneling activity and dump them outside.

The inside of the ant mound is a fascinating place with numerous tunnels and chambers. All these chambers have various purposes some of them are for:

  • storing of food
  • storing the wastes
  • keeping the eggs and the queen safe

Why do Ants make Mounds?

  • The excess soil deposits are the side product of the underground construction which are reused by the ants for making a proper entrance to their colony.
  • Apart from being the entrance of the nest, the mounds help in regulating the internal temperature as well as the moisture content of the underground colony.
  • Lastly, the mound helps in protecting the ant nest from direct predator attacks and provides just that extra cloak of safety.

Related: Why do Ants Climb Trees?

What are Ant Mounds Made Of?

Ant mounds are mainly composed of:

  • Ground soil
  • Various kinds of dirt
  • Sand
  • Twigs
  • Plant-based materials

Ants make sure that the mound is strong enough to put up with the passage of time. An ant mound is always made up of finer components and in most cases does not contain any heavy materials like pebbles and stones.

How are Anthills Built?

Anthills are built by the slow and steady work of the worker ants. They keep on digging and crafting underground tunnels and carry the excess unwanted soil material outside.

They use their strong mandibles to carry the soil and disposes of them right outside their entrance. They also carry out any kind of unwanted material present in the soil which basically qualifies as garbage for them.

Some ant varieties end up crafting this excess soil dump outside their entrance to give them a proper shape.

What Types of Ants Build Mounds?

Some specific varieties of ants can make ant mounds. These include:

  • Yellow Meadow ants
  • Argentine ants
  • Fire Ants
  • Harvester Ants
  • Texas leafcutter ants
  • Allegheny mound ants

Are Ant Mounds Dangerous?

Having ant nests near your house is never good news. It can be more troublesome in case, the ants are of the stinging type, as the fire ants. If you have children in the house this can be a really big worry.

In many instances, it gets tough to locate the ant nest as the majority of the ants don’t build mounds. However, if you can locate ant nests in form of mounds nearby your home, you should try to take the necessary actions to destroy the nest.

How to Find an Anthill

The best way to locate an anthill is by following the ant trail. However, not all ants built hills, the carpenter ants for example build their nests in wooden structures.

There is no guaranty that the anthills will have a proper structure, it can be present just in form of a pile of dirt. You can find them in open areas as well as at a corner of the backyard, just beside a tree or fences. In most instances, the anthills arise a few days after rainfall as it’s relatively easier to dig moist soil.

In case the anthill does not have an opening for an entrance then chances are high that you are looking at an ant mound made by the fire ants. Having colonies of fire ants out open in the yard can be quite dangerous. To be double sure take a look at the texture of the anthill. Does it look loosely built or has got a properly crafted structure?

Fire ants rapidly change colonies and hence are known to make loosely crafted ant mounds made of dirt and sand which are often dome or flat shaped.

“Why do I have Ant Hills in my Yard?”

Ants generally build their nest in places that have close proximity to food sources. So in case, you have an ant mound in your yard chances are high that they are obtaining their food from your home.

It is a sign that you should focus more on regular decluttering and cleanliness to make sure you don’t have garbage even up to a small extent piling up in your house. Make sure to maintain your lawn or yard regularly and treat it with insecticides from time to time.

How do you Get Rid of Anthills?

If you want to truly get rid of the anthills randomly popping up in your backyard you need to get rid of the ant colony. It is usually a good idea to seek pest control professionals.

If you just aim to destroy the anthill, you won’t be addressing the root cause and the ants will simply build another hill within a few days.

Seek help from professionals. They may use some of the below strategies.

Some of the most prominent ways of getting rid of anthills in the garden are:

1. Pouring Soapy Boiling Water

Yup, that is nasty, but it is the simplest yet most effective strategy to explore. They will take a kettle, fill it up with water, boil it and pour it down the opening of the anthill.

The water will flood the tunnels and interconnecting rooms whereas the heat will effectively get rid of the majority of the ant population.

To enhance the success rate of this mission of eradicating ants, soap can be added into the boiling water. The soap will make sure that the ants won’t find it easy to escape as they will get trapped in the sticky foamy liquid mixture.

2. Using Ant Bait

Ant baits are a slow method that can give you tremendous results. The baits are ant foods that contain a low amount of insecticides. After the worker ants carry them in the nest, the whole colony will feed upon it along with the larvae. Chances are high that within a few weeks, about 80% of the colony will die along with the queen ant. You may need to get this done a few times a year.

3. Using Insecticides

Pest control professionals can use ant insecticides and mix them with the boiling water and then pour them into the ant mounds.

Otherwise, they can use a powdery foam insecticide (often called ant killer dust) and sprinkle it around the ant mounds and in general around the lawn especially along with the corners and bushy areas.

Ask for Professional Assistance

If you have ant issues in the households and have pets and children in the house you need to make sure you deal with the ant colonies properly. If nothing seems to work for you or you want to avoid the hassle altogether, just seek professional guidance on the matter.


Ant mounds act as an extra layer of protection for the ant nests. They also help in the thermoregulation of the underground nest and also in controlling the humidity.

Unlike popular belief, ants dont normally reside in the ant mounds but live in the thorough network of tunnels and chambers located right below the anthill. The mound just acts as the tip of the iceberg.

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